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Zheng Z, Lu H, Lin Y, Shui L, Jin M, Jiang Z. Exploring the effect of high pressure in the denaturation of casein micelles by in-situ SERS. Food Chem 2024; 442:138359. [PMID: 38219564 DOI: 10.1016/j.foodchem.2024.138359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 12/29/2023] [Accepted: 01/02/2024] [Indexed: 01/16/2024]
Abstract
To investigate the structural changes of casein in response to the pressurization process under varying pressure levels, this study carried out both ex-situ and in-situ high-pressure experiments. In the in-situ experiments, the surface-enhanced Raman scattering (SERS) technique was combined with a diamond anvil cell (DAC). The high-pressure experiments indicated that significant dissociation of casein occurred at 200 MPa. Over the range of 0-302 MPa, casein exhibited both dissociation and aggregation behaviors. However, casein tended towards aggregation at pressures of 302-486 MPa, with a further increase observed beyond 486 MPa.
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Affiliation(s)
- Zhenhong Zheng
- College of Food Science, South China Agricultural University, Guangzhou 510640, China
| | - Han Lu
- International Academy of Optoelectronics at Zhaoqing, South China Normal University, Zhaoqing 526238, China; School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China
| | - Yingfeng Lin
- College of Food Science, South China Agricultural University, Guangzhou 510640, China
| | - Lingling Shui
- School of Information and Optoelectronic Science and Engineering, South China Normal University, Guangzhou 510006, China
| | - Mingliang Jin
- International Academy of Optoelectronics at Zhaoqing, South China Normal University, Zhaoqing 526238, China.
| | - Zhuo Jiang
- College of Food Science, South China Agricultural University, Guangzhou 510640, China.
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2
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Korkola NC, Stillman MJ. Human apo-metallothionein 1a is not a random coil: Evidence from guanidinium chloride, high temperature, and acidic pH unfolding studies. Biochim Biophys Acta Proteins Proteom 2024:141010. [PMID: 38490456 DOI: 10.1016/j.bbapap.2024.141010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/18/2024] [Accepted: 03/11/2024] [Indexed: 03/17/2024]
Abstract
The structures of apo-metallothioneins (apo-MTs) have been relatively elusive due to their fluxional, disordered state which has been difficult to characterize. However, intrinsically disordered protein (IDP) structures are rather diverse, which raises questions about where the structure of apo-MTs fit into the protein structural spectrum. In this paper, the unfolding transitions of apo-MT1a are discussed with respect to the effect of the chemical denaturant GdmCl, temperature conditions, and pH environment. Cysteine modification in combination with electrospray ionization mass spectrometry was used to probe the unfolding transition of apo-MT1a in terms of cysteine exposure. Circular dichroism spectroscopy was also used to monitor the change in secondary structure as a function of GdmCl concentration. For both of these techniques, cooperative unfolding was observed, suggesting that apo-MT1a is not a random coil. More GdmCl was required to unfold the protein backbone than to expose the cysteines, indicating that cysteine exposure is likely an early step in the unfolding of apo-MT1a. MD simulations complement the experimental results, suggesting that apo-MT1a adopts a more compact structure than expected for a random coil. Overall, these results provide further insight into the intrinsically disordered structure of apo-MT.
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Affiliation(s)
- Natalie C Korkola
- Department of Chemistry, The University of Western Ontario, 1151 Richmond St., London, ON N6A5B7, Canada
| | - Martin J Stillman
- Department of Chemistry, The University of Western Ontario, 1151 Richmond St., London, ON N6A5B7, Canada.
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3
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de Freitas Rocha J, de Castro Viana L, Filho LCPA, de Almeida TS, Neto JJL, Neto VV, Tabosa PMS, Nunes-Pinheiro DCS, Girão-Carmona VCC, Carvalho AFU, Mota EF. In vitro anti-inflammatory activity and ameliorative effects on gastric ulcers of Licania rigida benth seed extract. Inflammopharmacology 2023; 31:2631-2640. [PMID: 37420144 DOI: 10.1007/s10787-023-01283-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2023] [Accepted: 06/15/2023] [Indexed: 07/09/2023]
Abstract
Licania rigida Benth., a Brazilian endemic plant, has been traditionally used for treating inflammation and stomach pain. This work investigates the anti-inflammatory and gastroprotective activities of the ethanolic extract from L. rigida seeds (EELr) by in vitro and in vivo methods. The phytochemical profile was determined and the in vitro antioxidant activity was investigated by radical scavenging and thiobarbituric acid reactive substances methods. The ovalbumin denaturation method was used with sodium diclofenac as standard for the in vitro anti-inflammatory activity assessment. Acetylsalicylic acid was used to induce gastric ulcers in male mice and then to evaluate the preventive and therapeutic gastroprotective effect of EELr, using omeprazole as the reference drug. The extract exhibited relevant amount of phenolic compounds and flavonoids, in particular, demonstrating in vitro antioxidant capacity. EELr was able to inhibit almost 60% of ovalbumin denaturation at a concentration considered low. It also prevented the decrease of biochemical markers for oxidative stress such as superoxide dismutase (SOD) and reduced glutathione (GSH) in the stomach and SOD and catalase (CAT) in the liver. EELr also significantly decreased the number of lesions as well as reduced the ulcerated area when used as therapy. The observed effect may be due to its phenolic compounds, such as chlorogenic acid, caffeic acid and tannins, as previously reported. EELr is a potential source of compounds with anti-inflammatory activity, protects the liver from oxidative damage and improves healing of aspirin-induced ulcers. This work contributes to the knowledge of L. rigida species.
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Affiliation(s)
| | | | | | - Thiago Silva de Almeida
- Biochemistry and Molecular Biology Department, Federal University of Ceara, Fortaleza, CE, 60440-900, Brazil
- Laboratory of Phytochemistry and Process Integration, Northeast Strategic Technologies Center-CETENE, Recife, Pernambuco, 50740-545, Brazil
| | - José Joaquim Lopes Neto
- Biochemistry and Molecular Biology Department, Federal University of Ceara, Fortaleza, CE, 60440-900, Brazil
- Pharmacy Course, Estacio São Luís University Center, São Luís, Maranhão, 65020-250, Brazil
| | - Veríssimo Vieira Neto
- Biochemistry and Molecular Biology Department, Federal University of Ceara, Fortaleza, CE, 60440-900, Brazil
| | - Pedro Matheus Sousa Tabosa
- Biochemistry and Molecular Biology Department, Federal University of Ceara, Fortaleza, CE, 60440-900, Brazil
| | | | | | | | - Erika Freitas Mota
- Biology Department, Federal University of Ceara, Fortaleza, CE, 60440-900, Brazil.
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4
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Wang C, Rao J, Li X, He D, Zhang T, Xu J, Chen X, Wang L, Yuan Y, Zhu X. Chickpea protein hydrolysate as a novel plant-based cryoprotectant in frozen surimi: Insights into protein structure integrity and gelling behaviors. Food Res Int 2023; 169:112871. [PMID: 37254320 DOI: 10.1016/j.foodres.2023.112871] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Revised: 03/07/2023] [Accepted: 04/19/2023] [Indexed: 06/01/2023]
Abstract
Chickpea protein (CP) and its enzymatic hydrolysates are one of the most widely consumed pulse ingredients manifesting versatile applications in food industry, such as binders, emulsifiers, and meat protein substitutes. Other than those well-known functionalities, however, the use of CP as a cryoprotectant remained unexplored. In this study, we prepared the chickpea protein hydrolysate (CPH) and investigated its cryoprotective effects to frozen surimi in terms of the protein structure integrity and gelling behaviors. Results indicated that CPH could inhibit myofibrillar protein (MP) denaturation and oxidation during the freeze-thaw cycling, as evidenced by their increased solubility, Ca2+-ATPase activity, sulfhydryl concentration, and declined content of disulfide bonds, carbonyl concentration and surface hydrophobicity. Freezing-induced changes on MP secondary structures were also retarded. Moreover, gels prepared from CPH-protected frozen surimi demonstrated more stabilized microstructure, uniform water distribution, enhanced elasticity, gel strength and water holding capacity. The CPH alone, at a reducing addition content of 4% (w/w), exhibited comparable cryoprotective performance to that of the commercial formulation (4% sucrose and 4% sorbitol). Therefore, this study provides scientific insights for development of pulse proteins as novel and high-performance food cryoprotectants.
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Affiliation(s)
- Chao Wang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Junhui Rao
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Xueyin Li
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Diheng He
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Ting Zhang
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Jianteng Xu
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China
| | - Xi Chen
- Key Laboratory of Bulk Grain and Oil Deep Processing Ministry of Education, Wuhan Polytechnic University, Wuhan 430023, China
| | - Lan Wang
- Institute for Farm Products Processing and Nuclear-Agricultural Technology, Hubei Academy of Agricultural Science, Wuhan 430064, China
| | - Yue Yuan
- Center for Nanophase Materials and Sciences, Oak Ridge National Laboratory, Oak Ridge, TN 37830, United States
| | - Xiangwei Zhu
- National "111" Center for Cellular Regulation and Molecular Pharmaceutics, Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei University of Technology, Wuhan 430068, China.
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5
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Li J, Liu J, Xiao G, Li L, Xu Y, Yu Y, Liang Z, Xu S, Cheng L. Effects of high pressure synergistic enzymatic physical state and concentration on the denaturation of polyphenol oxidase. Food Chem 2023; 428:136703. [PMID: 37423103 DOI: 10.1016/j.foodchem.2023.136703] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 06/10/2023] [Accepted: 06/20/2023] [Indexed: 07/11/2023]
Abstract
The synergistic effect of the initial state of the enzyme and pressure level on the denaturation of PPO has not been clear yet, but it significantly affects the application of high hydrostatic pressure (HHP) in the enzyme-containing food processing. Solid (S-) and low/high concentration liquid (LL-/HL-) polyphenol oxidase (PPO) was used as the study object, and the microscopic conformation, molecular morphology and macroscopic activity of PPO under HHP treatments (100-400 MPa, 25 °C/30 min) were investigated by spectroscopic techniques. The results show that the initial state has a significant effect on the activity, structure, active force and substrate channel of PPO under pressure. The effec can be ranked as follows: physical state > concentration > pressure, S-PPO > LL-PPO > HL-PPO. High concentration has a weakening effect on the pressure denaturation of the PPO solution. Under high pressure, the α-helix and concentration factors play a crucial role in stabilizing the structure.
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Affiliation(s)
- Jinghao Li
- Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural, Guangzhou 510610, China; Zhongkai University of Agricultural and Engineering, Guangzhou 510631, China
| | - Jie Liu
- Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural, Guangzhou 510610, China
| | - Gengsheng Xiao
- Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural, Guangzhou 510610, China; Zhongkai University of Agricultural and Engineering, Guangzhou 510631, China.
| | - Lu Li
- Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural, Guangzhou 510610, China
| | - Yujuan Xu
- Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural, Guangzhou 510610, China; Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou 510610, China
| | - Yuanshan Yu
- Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural, Guangzhou 510610, China
| | - Zhanhong Liang
- Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural, Guangzhou 510610, China
| | - Sai Xu
- Institute of Facility Agriculture, Guangdong Academy of Agriculture Sciences
| | - Lina Cheng
- Sericultural & Argi-Food Research Institute, Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural, Guangzhou 510610, China.
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6
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Denzer M, Furbeck R, Sullivan G, Danao MG, Mafi GG, Ramanathan R. Sarcoplasmic model to study the effects of high-pressure processing on beef color. Meat Sci 2023; 199:109127. [PMID: 36739704 DOI: 10.1016/j.meatsci.2023.109127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/20/2023] [Accepted: 01/23/2023] [Indexed: 01/28/2023]
Abstract
High-pressure processing (HPP) negatively impacts fresh meat color. The objective of the study was to use a sarcoplasmic (meat extract) model to better understand the effects of HPP on meat color. Sarcoplasm was extracted at pHs of 5.6, 6.0, or 6.4 and fractioned based on centrifugation speed at 0, 3500 g, and 15,000 g for 5 min. The extracts were processed using a commercial HPP unit at 300 MPa, 450 MPa, and 600 MPa, along with a non-pressurized control. Myoglobin concentration decreased (P < 0.05) with increased HPP levels. Sarcoplasm treated with 300 MPa had the greatest oxymyoglobin content (P < 0.05) compared with the non-pressurized control and other HPP levels. Deoxymyoglobin and metmyoglobin content were greater at 600 MPa compared with non-pressurized control and other HPP levels. In summary, higher pH and lower pressure can improve redness of sarcoplasm.
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7
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Song H, Wang Y, Dong W, Chen Q, Sun H, Peng H, Li R, Chang Y, Luo H. Effect of SpyTag/SpyCatcher cyclization on stability and refolding of green fluorescent protein. Biotechnol Lett 2022; 44:613-621. [PMID: 35359178 DOI: 10.1007/s10529-022-03246-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 03/15/2022] [Indexed: 11/26/2022]
Abstract
To study the effect of SpyTag/SpyCatcher cyclization on stability and refolding of protein, we constructed a cyclized green fluorescent protein (SRGFP) and its derivative to act as a linear structure control (L-SRGFP). SRGFP and L-SRGFP showed similar fluorescence characteristics to the wild-type GFP, while compared with GFP and L-SRGFP, the thermal stability and denaturation resistance of SRGFP were improved. The refolding efficiencies of these three denatured proteins were investigated under different pH, temperature and initial protein concentration conditions, and it was found that SRGFP was superior to GFP and L-SRGFP in terms of refolding yield and refolding speed. In the pH range of 8.0-8.5, SRGFP could basically recover all fluorescence, while GFP and L-SRGFP recovered only about 87.52% and 88.58%. When refolded at a high temperature (37 °C), SRGFP still recovered 85.27% of the fluorescence, whereas GFP and L-SRGFP recovered only around 69.43% and 68.45%. At a high initial protein concentration (5 mg/mL), the refolding yield of SRGFP was about 15% higher than that of both GFP and L-SRGFP. These results suggest that the introduction of SpyRing structure (head-to-tail cyclization via SpyTag and SpyCatcher) improved the protein's stability and facilitated the refolding of denatured protein.
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Affiliation(s)
- Haiyan Song
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Yue Wang
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Wenge Dong
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Qiwei Chen
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Hongxu Sun
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
| | - Hui Peng
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Ren Li
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China
| | - Yanhong Chang
- Department of Environmental Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
- Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants, Beijing, 100083, China.
| | - Hui Luo
- Department of Biological Science and Engineering, University of Science and Technology Beijing, Beijing, 100083, China.
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8
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Khaibrakhmanova D, Nikiforova A, Li Z, Sedov I. Effect of ligands with different affinity on albumin fibril formation. Int J Biol Macromol 2022; 204:709-717. [PMID: 35134455 DOI: 10.1016/j.ijbiomac.2022.01.189] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 01/11/2022] [Accepted: 01/29/2022] [Indexed: 11/18/2022]
Abstract
The effect of binding of several ligands to bovine serum albumin on the kinetics of fibril formation at denaturing conditions is studied. The considered ligands are clinical drugs with different binding constants to albumin: relatively strong binders (naproxen, ibuprofen, warfarin with 105 to 107 binding constant values) and weak binders (isoniazid, ranitidine with 103 to 104 binding constant values). The data of thioflavin fluorescence binding assay, Congo red binding assay, and circular dichroism spectroscopy indicate ligand concentration-dependent suppression of fibril formation in the presence of strong binders and no effects in the presence of weak binders. Analysis of kinetic curves shows no induction lag associated with fibril nucleation and the first-order kinetics of fibril formation with respect to albumin concentration for all the studied systems. Using DSC method, the fractions of unfolded albumin at incubation temperature were determined for each albumin-ligand system and ligand concentration. Their magnitudes ranging from 0 to 1 correlate with the initial rates of fibril formation and with equilibrium concentrations of fibrils formed in the system after incubation for at least 120 min. The results indicate that fibrils are formed from partially or completely denatured albumin form with the rate proportional to the fraction of this form. Strong albumin binders act as thermodynamic inhibitors of fibrillation shifting the unfolding equilibrium to the side of the native ligand-bound protein.
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Affiliation(s)
| | - Alena Nikiforova
- Chemical Institute, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia
| | - Ziying Li
- Chemical Institute, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia
| | - Igor Sedov
- Chemical Institute, Kazan Federal University, Kremlevskaya 18, 420008 Kazan, Russia.
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9
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Eronina TB, Mikhaylova VV, Chebotareva NA, Kleymenov SY, Pivovarova AV, Kurganov BI. Combined action of chemical chaperones on stability, aggregation and oligomeric state of muscle glycogen phosphorylase b. Int J Biol Macromol 2022; 203:406-416. [PMID: 35066023 DOI: 10.1016/j.ijbiomac.2022.01.106] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/10/2022] [Accepted: 01/17/2022] [Indexed: 01/19/2023]
Abstract
Chemical chaperones are a class of small molecules, which enhance protein stability, folding, inhibit protein aggregation, and are used for long-term storage of therapeutic proteins. The combined action of chemical chaperones trehalose, betaine and lysine on stability, aggregation and oligomeric state of muscle glycogen phosphorylase b (Phb) has been studied. Dynamic light scattering data indicate that the affinity of trehalose to Phb increased in the presence of betaine or lysine at both stages (stage of nucleation and aggregate growth) of enzyme aggregation at 48 °C, in contrast, the affinity of betaine to the enzyme in the presence of lysine remained practically unchanged. According to differential scanning calorimetry and analytical ultracentrifugation data, the mixture of trehalose and betaine stabilized Phb stronger than either of them in total. Moreover, the destabilizing effect of lysine on the enzyme was almost completely compensated by trehalose and only partially by betaine. The main protective effect of the mixtures of osmolytes and lysine is associated with their influence on the dissociation/denaturation stage, which is the rate-limiting one of Phb aggregation. Thus, a pair of chaperones affects the stability, oligomeric state, and aggregation of Phb differently than individual chaperones.
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Affiliation(s)
- Tatiana B Eronina
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia.
| | - Valeriya V Mikhaylova
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia
| | - Natalia A Chebotareva
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia
| | - Sergey Y Kleymenov
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia; Koltsov's Institute of Developmental Biology, Russian Academy of Sciences, Vavilova 26, Moscow 119991, Russia
| | - Anastasia V Pivovarova
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia
| | - Boris I Kurganov
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia
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10
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Tan M, Ding Z, Mei J, Xie J. Effect of cellobiose on the myofibrillar protein denaturation induced by pH changes during freeze-thaw cycles. Food Chem 2021; 373:131511. [PMID: 34763934 DOI: 10.1016/j.foodchem.2021.131511] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 10/07/2021] [Accepted: 10/29/2021] [Indexed: 11/04/2022]
Abstract
The aim of this study was to investigate myofibrillar protein (MFP) denaturation induced by pH changes during freeze-thaw (FT) cycles, and to propose an effective mitigation strategy. Owing to the selective crystallization of Na2HPO4·12H2O and the consequent pH change, a pH change of 3.32 units was observed when the MFP solution were frozen. The surface hydrophobicity, particle size and confocal laser scanning microscopy showed that the protein molecules gradually unfolded and formed larger protein aggregation as the number of FT cycles increases. Additionally, protein degradation, secondary and tertiary structure alterations suggested that the FT cycle could disrupt structural integrity. The addition of cellobiose could maximize the inhibition of pH changes (decrease of ∼0.62 unit), no Na2HPO4·12H2O crystallization was observed by X-ray diffraction. Cellobiose could minimize FT damage to myofibrillar protein, which was closest to the control. Thus, cellobiose can be used as a new and effective cryoprotectant.
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Affiliation(s)
- Mingtang Tan
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China
| | - Zhaoyang Ding
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquatic Product Processing&Preservation, Shanghai 201306, China; Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai 201306, China; National Experimental Teaching Demonstration Center for Food Science and Engineering, Shanghai Ocean University, Shanghai 201306, China.
| | - Jun Mei
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquatic Product Processing&Preservation, Shanghai 201306, China; Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai 201306, China; National Experimental Teaching Demonstration Center for Food Science and Engineering, Shanghai Ocean University, Shanghai 201306, China.
| | - Jing Xie
- College of Food Science and Technology, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquatic Product Processing&Preservation, Shanghai 201306, China; Professional Technology Service Platform on Cold Chain Equipment Performance and Energy Saving Evaluation, Shanghai 201306, China; National Experimental Teaching Demonstration Center for Food Science and Engineering, Shanghai Ocean University, Shanghai 201306, China.
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11
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Barros CA, Sanches D, Marques de Carvalho CA, Santos RA, Ferraz de Souza TL, Macena Leite VL, Pereira da Costa Campos S, Cheble de Oliveira A, Gonçalves RB. Influence of iron binding in the structural stability and cellular internalization of bovine lactoferrin. Heliyon 2021; 7:e08087. [PMID: 34632151 DOI: 10.1016/j.heliyon.2021.e08087] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 08/20/2021] [Accepted: 09/26/2021] [Indexed: 02/05/2023] Open
Abstract
Lactoferrin (Lf) is an iron-binding glycoprotein and a component of many external secretions with a wide diversity of functions. Structural studies are important to understand the mechanisms employed by Lf to exert so varied functions. Here, we used guanidine hydrochloride and high hydrostatic pressure to cause perturbations in the structure of bovine Lf (bLf) in apo and holo (unsaturated and iron-saturated, respectively) forms, and analyzed conformational changes by intrinsic and extrinsic fluorescence spectroscopy. Our results showed that the iron binding promotes changes on tertiary structure of bLf and increases its structural stability. In addition, we evaluated the effects of bLf structural change on the kinetics of bLf internalization in Vero cells by confocal fluorescence microscopy, and observed that the holo form was faster than the apo form. This finding may indicate that structural changes promoted by iron binding may play a key role in the intracellular traffic of bLf. Altogether, our data improve the comprehension of bLf stability and uptake, adding knowledge to its potential use as a biopharmaceutical.
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Khalesi M, FitzGerald RJ. Investigation of the flowability, thermal stability and emulsification properties of two milk protein concentrates having different levels of native whey proteins. Food Res Int 2021; 147:110576. [PMID: 34399548 DOI: 10.1016/j.foodres.2021.110576] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 06/23/2021] [Accepted: 06/27/2021] [Indexed: 11/28/2022]
Abstract
Milk protein concentrate-85 (MPC85) is a dairy ingredient which has a diverse range of applications in food products. The technofunctional properties of two MPC85 samples having similar gross composition but different levels of native whey protein (WP), i.e., MPC85S1 and MPC85S2 with 16.6 and 6.0 g native WP/100 g protein, respectively, were compared. Rheometeric analysis showed that under an applied normal stress of 1.0-15.0 kPa, the compressibility, the air permeability and the cohesiveness of MPC85S2 was higher compared to MPC85S1. Differential scanning calorimetry showed that protein denaturation in MPC85S1 began at 63 °C while for MPC85S2 it began at 70 °C. The heat coagulation time (HCT at 140 °C) for 4.2% (w/v, on a protein basis) reconstituted MPC85S1 and MPC85S2 was 2.2 and 2.7 min, respectively. While a higher lightness for MPC85S1 was evidenced using colourimeter analysis, the colour stability on oven drying at 95 °C for MPC85S2 was higher than MPC85S1. The emulsion produced with MPC85S1 flocculated after 1 d and phase separation occurred after 14 d. In the case of MPC85S2, flocculation began after 4 d while phase separation was observed at 33 d. The viscosity of MPC85S2 (4.2% (w/v) protein) was higher than MPC85S1. This study showed differences between the flowability, viscosity, colour properties, thermal stability (in powder and in reconstituted format), emulsification and buffering capacity for MPC samples having two different levels of WP denaturation. The results demonstrated that the MPCs studied having two different levels of WP denaturation could be targeted for different functional applications. The minimal/maximum level of denaturation required to induce technofunctional property differences requires further study.
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13
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Li S, Ye A, Singh H. The effect of ultrafiltration on the acid gelation properties of protein-standardised skim milk systems. Food Res Int 2021; 146:110432. [PMID: 34119241 DOI: 10.1016/j.foodres.2021.110432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 04/21/2021] [Accepted: 05/21/2021] [Indexed: 11/24/2022]
Abstract
In this study, we investigated the impact of ultrafiltration (UF) on the acid gelation of milk using two protein-standardised milk systems, consisting of either skim milk and retentate (SR) or permeate and retentate (PR), over different seasons in New Zealand. The composition and the physicochemical properties of the two systems before heating were comparable, whereas the levels of heat-induced α-lactalbumin denaturation and the association of the casein micelles with α-lactalbumin were significantly lower in PR than in SR. PR displayed superior acid gelation properties compared with SR, which was most pronounced in the late season. The structural modifications of the whey proteins and casein micelles that were induced by UF and the re-equilibration of calcium in the milk mixtures may have affected the acid gelation properties of the milk by influencing the denaturation and micelle association of the whey proteins. The results suggest that UF has the potential as a tool for tuning the acid gelation properties of milk.
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14
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Miyafusa T, Watanabe H, Honda S. Local disorder of the C-terminal segment of the heavy chain as a common sign of stressed antibodies evidenced with a peptide affinity probe specific to non-native IgG. Int J Biol Macromol 2021; 182:1697-1703. [PMID: 34048835 DOI: 10.1016/j.ijbiomac.2021.05.137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Revised: 05/20/2021] [Accepted: 05/20/2021] [Indexed: 11/24/2022]
Abstract
Therapeutic antibodies have many biopharmaceutical applications; however, characterization of their higher-order structures is a major concern in quality control. We have developed AF.2A1, an artificial protein, that specifically recognizes non-native, structured IgGs. We performed binding assays using various types of IgGs and fragments to investigate the mechanisms by which AF.2A1 interacts with the non-native IgG. AF.2A1 recognized the acid-stressed IgGs from human, mouse, and rat, but not rabbit. Binding assays using the human IgG1 fragments revealed that an interface emerged by deleting five C-terminal residues. We conclude that AF.2A1 recognizes an exposed hydrophobic core centered on the Trp417. Our results concur with those of the previous studies showing that C-terminal structural changes occur early during antibody denaturation and aggregation. Our findings explain the molecular rationale for using AF.2A1 in quality control of biopharmaceutical IgGs.
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Affiliation(s)
- Takamitsu Miyafusa
- Biomedical Research Institute, The National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan; Bioprocess Research Institute, The National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Hideki Watanabe
- Biomedical Research Institute, The National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Shinya Honda
- Biomedical Research Institute, The National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan.
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15
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Ermakova EA, Makshakova ON, Zuev YF, Sedov IA. Fibril fragments from the amyloid core of lysozyme: An accelerated molecular dynamics study. J Mol Graph Model 2021; 106:107917. [PMID: 33887522 DOI: 10.1016/j.jmgm.2021.107917] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 03/30/2021] [Accepted: 04/02/2021] [Indexed: 10/21/2022]
Abstract
Protein aggregation and formation of amyloid fibrils are associated with many diseases and present a ubiquitous problem in protein science. Hen egg white lysozyme (HEWL) can form fibrils both from the full length protein and from its fragments. In the present study, we simulated unfolding of the amyloidogenic fragment of HEWL encompassing residues 49-101 to study the conformational aspects of amyloidogenesis. The accelerated molecular dynamics approach was used to speed up the sampling of the fragment conformers under enhanced temperature. Analysis of conformational transformation and intermediate structures was performed. During the unfolding, the novel short-living and long-living β-structures are formed along with the unstructured random coils. Such β-structure enriched monomers can interact with each other and propagate into fibril-like forms. The stability of oligomers assembled from these monomers was evaluated in the course of MD simulations with explicit water. The residues playing a key role in fibril stabilization were determined. The work provides new insights into the processes occurring at the early stages of amyloid fibril assembly.
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Affiliation(s)
- Elena A Ermakova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Lobachevsky Str., 2/31, 420111, Kazan, Russia; Sirius University of Science and Technology, Olympic Ave, 1, 354340, Sochi, Russia.
| | - Olga N Makshakova
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Lobachevsky Str., 2/31, 420111, Kazan, Russia; Sirius University of Science and Technology, Olympic Ave, 1, 354340, Sochi, Russia
| | - Yuriy F Zuev
- Kazan Institute of Biochemistry and Biophysics, FRC Kazan Scientific Center of RAS, Lobachevsky Str., 2/31, 420111, Kazan, Russia
| | - Igor A Sedov
- Kazan Federal University, Kremlevskaya Str.,18, 420111, Kazan, Russia; Sirius University of Science and Technology, Olympic Ave, 1, 354340, Sochi, Russia
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16
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Abstract
Animal venom is a rich source for peptide toxins that bind and modulate the function of ion channels. Owing to their ability to bind receptor sites on the channel protein with high affinity and specificity, peptide neurotoxins have become an indispensable tool for ion channel research. Recent breakthroughs in structural biology and advances in computer simulations of biomolecules have sparked a new interest in animal toxins as probes of channel protein structure and function. Here, we focus on methods used to produce animal toxins for research purposes using recombinant expression. The specific challenges associated with heterologous production of venom peptides are discussed, and several methods targeting these issues are presented with an emphasis on E. coli based systems. An efficient protocol for the bacterial expression, folding, and purification of recombinant venom peptides is described.
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Affiliation(s)
- Chandamita Saikia
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Gili Ben-Nissan
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel
| | - Eitan Reuveny
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
| | - Izhar Karbat
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel.
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17
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Acosta EV, Ospina-E JC, Muñoz DA, Alvarez H. Towards a phenomenological based model for predicting the hardness of a processed meat product. J Food Sci Technol 2021; 58:701-709. [PMID: 33568864 PMCID: PMC7847885 DOI: 10.1007/s13197-020-04584-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 12/04/2019] [Accepted: 06/12/2020] [Indexed: 10/23/2022]
Abstract
This study aims to build a model for predicting the hardness of meat products by considering their protein fractions and protein structural changes during production. Protein solubility is considered an indicator of protein structural changes. The obtained model results show that structural changes of sarcoplasmic and myofibrillar proteins occur during production. The gelling capacity is formed by the effect of the three protein fractions, namely myofibrillar, sarcoplasmic and stromal. The obtained model allows the prediction of the hardness of meat products based on their protein fraction contents with error below 5%, thus reaching a significant adjustment between real process data and the simulated model.
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Affiliation(s)
- Elly V. Acosta
- Industria de Alimentos Zenú S.A.S., Centro de Investigación y Desarrollo Cárnico CI+D, Cra 64C, 104-03 Medellín, Colombia
| | - Juan C. Ospina-E
- Industria de Alimentos Zenú S.A.S., Centro de Investigación y Desarrollo Cárnico CI+D, Cra 64C, 104-03 Medellín, Colombia
| | - Diego A. Muñoz
- ÓPTIMO, Optimización Matemática de Procesos ÓPTIMO, Centro de Ciencia Básica, Universidad Pontificia Bolivariana, Circular 1, 70-01, Medellín, Colombia
| | - Hernan Alvarez
- KALMAN, Grupo de investigación en Procesos Dinámicos, Universidad Nacional de Colombia-Sede Medellín, Cra 80, 65-223, Medellín, Colombia
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18
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Preisz Z, Kunsági-Máté S. Effect of methotrexate and its photodegradation products on the temperature induced denaturation of human serum albumin. Spectrochim Acta A Mol Biomol Spectrosc 2021; 245:118905. [PMID: 32927299 DOI: 10.1016/j.saa.2020.118905] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/03/2020] [Revised: 08/25/2020] [Accepted: 08/29/2020] [Indexed: 06/11/2023]
Abstract
Effect of the photodegradation of chemotherapeutic agent methotrexate on the denaturation of human serum albumin has been studied by differential scanning calorimetry and fluorimetric measurements. Photoluminescence studies highlighted entropy driven binding of both methotrexate molecules and its degradation products to the albumin molecules. The calorimetric measurements evaluated by the Kissinger method show elevated activation energy in the presence of methotrexate. Similar but moderated enhancement of the activation energy was obtained in the presence of the photodegradation products of methotrexate. These results highlight stabilization of the human serum albumin by the methotrexate drug which finding may contribute to fine tuning of methotrexate applications in therapy.
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Affiliation(s)
- Zsolt Preisz
- Department of General and Physical Chemistry, Faculty of Sciences, University of Pécs, Ifjúság 6, H-7624 Pécs, Hungary; Institute of Organic and Medicinal Chemistry, Medical School, University of Pécs, Szigeti 12, H-7624 Pécs, Hungary.
| | - Sándor Kunsági-Máté
- Department of General and Physical Chemistry, Faculty of Sciences, University of Pécs, Ifjúság 6, H-7624 Pécs, Hungary; Institute of Organic and Medicinal Chemistry, Medical School, University of Pécs, Szigeti 12, H-7624 Pécs, Hungary; JánosSzentágothai Research Center, University of Pécs, Ifjúság 20, H-7624 Pécs, Hungary.
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19
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Guckeisen T, Hosseinpour S, Peukert W. Effect of pH and urea on the proteins secondary structure at the water/air interface and in solution. J Colloid Interface Sci 2021; 590:38-49. [PMID: 33524719 DOI: 10.1016/j.jcis.2021.01.015] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 01/09/2023]
Abstract
HYPOTHESIS The secondary structure of proteins affects their functionality and performance in physiological environments or industrial applications. Change of the solution pH or the presence of protein denaturants are the main chemical means that can alter the secondary structure of proteins or lead to protein denaturation. Since proteins in the bulk solution and those residing at the solution/air interface experience different local environments, their response to chemical denaturation can be different. EXPERIMENTS We utilize circular dichroism and chiral/achiral sum frequency generation spectroscopy to study the secondary structure of selected proteins as a function of the solution pH or in the presence of 8 M urea in the bulk solution and at the solution/air interface, respectively. FINDINGS The liquid/air interface can enhance or decrease protein conformation stability. The change in the secondary structure of the surface adsorbed proteins in alkaline solutions occurs at pH values lower than those denaturing the studied proteins in the bulk solution. In contrast, while 8 M urea completely denatures the studied proteins in the bulk solution, the liquid/air interface prevents the urea-induced denaturation of the surface adsorbed proteins by limiting the access of urea to the hydrophobic side chains of proteins protruding to air.
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Affiliation(s)
- Tobias Guckeisen
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität-Erlangen-Nürnberg (FAU), Cauerstraße 4, 91058 Erlangen, Germany.
| | - Saman Hosseinpour
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität-Erlangen-Nürnberg (FAU), Cauerstraße 4, 91058 Erlangen, Germany.
| | - Wolfgang Peukert
- Institute of Particle Technology (LFG), Friedrich-Alexander-Universität-Erlangen-Nürnberg (FAU), Cauerstraße 4, 91058 Erlangen, Germany.
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20
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Eronina TB, Mikhaylova VV, Chebotareva NA, Shubin VV, Kleymenov SY, Kurganov BI. Effect of arginine on stability and aggregation of muscle glycogen phosphorylase b. Int J Biol Macromol 2020; 165:365-374. [PMID: 32961195 DOI: 10.1016/j.ijbiomac.2020.09.101] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/14/2020] [Accepted: 09/14/2020] [Indexed: 11/26/2022]
Abstract
Arginine (Arg) is frequently used in biotechnology and pharmaceutics to stabilize protein preparations. When using charged ions like Arg, it is necessary to take into account their contribution to the increase in ionic strength, in addition to the effect of Arg on particular processes occurring under the conditions of constancy of ionic strength. Here, we examined contribution of ionic strength (0.15 and 0.5 M) to the effects of Arg on denaturation, thermal inactivation and aggregation of skeletal muscle glycogen phosphorylase b (Phb). Dynamic light scattering, analytical ultracentrifugation, differential scanning calorimetry, circular dichroism and enzymatic activity assay were used to assess the effects of Arg at constant ionic strength compared with the effects of ionic strength alone. We found that high ionic strength did not affect the secondary structure of Phb, but changed conformation of the protein. Such a destabilization of the enzyme causes an increase in the initial rate of aggregation and inactivation of Phb thereby affecting its denaturation. Binding of Arg causes additional changes in the protein conformation, weakening the bonds between monomers in the dimer. This causes the dimer to dissociate into monomers, which rapidly aggregate. Thus, Arg acts on these processes much stronger than just ionic strength.
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Affiliation(s)
- Tatiana B Eronina
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia
| | - Valeriya V Mikhaylova
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia
| | - Natalia A Chebotareva
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia
| | - Vladimir V Shubin
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia
| | - Sergey Y Kleymenov
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia; Koltzov Institute of Developmental Biology, Russian Academy of Sciences, Vavilova 26, Moscow 119991, Russia
| | - Boris I Kurganov
- Bach Institute of Biochemistry, Federal Research Centre "Fundamentals of Biotechnology", Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia.
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21
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Derman İD, Şenel EC, Ferhanoğlu O, Çilesiz İ, Kazanci M. Effect of Heat Level and Expose Time on Denaturation of Collagen Tissues. Cell Mol Bioeng 2020; 14:113-119. [PMID: 33643470 DOI: 10.1007/s12195-020-00653-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 09/16/2020] [Indexed: 10/23/2022] Open
Abstract
Introduction The applied heat level and expose time are main issues in certain operations/applications, such as a laser assisted tissue welding, preparation of collagen-based biomaterials (films, implants). Therefore, the precise investigation of these parameters is crucial. The results can serve as a guideline to assess potential effects while maintaining the functionality of the collagen structures. Methods Collagen tissues from rat-tail tendon, calfskin, and bones are soaked in buffer solutions, then examined by microscope at different temperature levels. Results Increase in temperature reduced the microscopically observed collagen crimp contrast for calfskin and rat-tail tendons but not for bone tissues. The contrast level for rat tail tendon decreased down to 80% of its initial value at 37, 157, and 266 s for 70, 65, and 60 °C, respectively. The decrease in the crimp contrast was about only 25% and 2% at 55 and 50 °C after 2 h, respectively. 50% drop in contrast level was occurred for the skin samples at 16, 90, 110 and 1900 s for 70, 65, and 60 °C, respectively. The bone samples, did not show any significant differences in contrast levels. Conclusion The observed denaturation behaviours are in line with Arrhenius Law. This study could be expanded on to other types of tissues at wider temperature ranges to make a guideline for biological/medical processes that radiate heat in order to assess their side effects on collagen and other proteins.
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Affiliation(s)
- İrem Deniz Derman
- Electronics and Communication Engineering, Istanbul Technical University, 34469 Istanbul, Turkey.,Biomedical Engineering Graduate Program, Istanbul Technical University, 34469 Istanbul, Turkey
| | - Esat Can Şenel
- Electronics and Communication Engineering, Istanbul Technical University, 34469 Istanbul, Turkey.,Biomedical Engineering Graduate Program, Istanbul Technical University, 34469 Istanbul, Turkey
| | - Onur Ferhanoğlu
- Electronics and Communication Engineering, Istanbul Technical University, 34469 Istanbul, Turkey
| | - İnci Çilesiz
- Electronics and Communication Engineering, Istanbul Technical University, 34469 Istanbul, Turkey
| | - Murat Kazanci
- Biomedical Engineering Department, School of Engineering and Natural Sciences, Istanbul Medeniyet University, 34700 Istanbul, Turkey
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22
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Fueki T, Tanaka K, Obara K, Kawahara R, Namiki T, Makino T. The acrid raphides in tuberous root of Pinellia ternata have lipophilic character and are specifically denatured by ginger extract. J Nat Med 2020; 74:722-731. [PMID: 32591979 PMCID: PMC7929962 DOI: 10.1007/s11418-020-01425-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 06/12/2020] [Indexed: 10/27/2022]
Abstract
Unprocessed dried tuberous root of Pinellia ternata (Pinellia Tuber) has been used as a component of traditional Japanese Kampo medicine, while this crude drug is usually used after processing with Ginger in traditional Chinese medicine (TCM). It is known that the raphides contained in unprocessed Pinellia Tuber can induce severe acrid irritation of the oral and laryngopharynx mucosa when it is boiled insufficiently. However, the mechanism of the inducing irritation by the raphides nor that of the detoxification by heat or processing with Ginger have been left unclear, mainly because of the difficulties in the extraction and the purification of the raphides and in the assays of acridity. In this study, we developed an easy protocol that can be used to collect raphides from unprocessed Pinellia Tuber and an assay protocol that can be used to evaluate the acridity of the raphides in vitro. The raphides of Pinellia Tuber were discovered to have a lipophilic character and to be collected easily by the extraction using petroleum ether. It was also found that the denaturation of the raphides could be assayed by the dispersity of them in petroleum ether layer of the water/petroleum ether partition, and the acridity of the raphides was found to be in correlation with the assayed denaturation. The raphides were denatured by heat, methanol, or Ginger extract and the denaturing activity of Ginger on raphides was found to be attributable to its lipophilic and thermostable components, which may explain the meaning of the processing of Pinellia Tuber with Ginger in TCM, and may lead to the development of an easier and safer protocol to administer Pinellia Tuber. In addition, it was found that rinsing the mouth with salad oil can effectively relieve irritation of the oral mucosa caused by unprocessed Pinellia Tuber, probably due to the lipophilicity of the raphides.
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Affiliation(s)
- Tsukasa Fueki
- Matsuya Pharmacy, Niigata, Japan
- Department of Traditional Medicine, Toho University School of Medicine, Tokyo, Japan
- Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Koichiro Tanaka
- Department of Traditional Medicine, Toho University School of Medicine, Tokyo, Japan
| | - Kunihiko Obara
- Department of Traditional Medicine, Toho University School of Medicine, Tokyo, Japan
- Obara Coloproctology Clinic, Tokyo, Japan
| | - Ryudo Kawahara
- Department of Traditional Medicine, Toho University School of Medicine, Tokyo, Japan
- Department of Cardiology, Tokyo Nishi Tokushukai Hospital, Tokyo, Japan
| | - Takao Namiki
- Department of Japanese-Oriental (Kampo) Medicine, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Toshiaki Makino
- Department of Pharmacognosy, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan.
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23
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Cheng L, Zhu Z, Sun DW. Impacts of high pressure assisted freezing on the denaturation of polyphenol oxidase. Food Chem 2020; 335:127485. [PMID: 32763785 DOI: 10.1016/j.foodchem.2020.127485] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 06/22/2020] [Accepted: 07/01/2020] [Indexed: 02/08/2023]
Abstract
The mechanism of enzyme protein denaturation induced by high pressure freezing is complicated and unclear as this process involves Pressure-Factors (pressure and time) and Freezing-Factors (temperature, phase transition, recrystallization, and ice crystal types). In this study, the thermodynamics and conformation changes of mushroom polyphenol oxidase (PPO) under high pressure freezing treatments (HPF, 100,150,200,300,400,500MPaP-20°C/30min) and high pressure processes (HPP) followed with normal pressure immersion freezing (HPP-IF, 100-500MPaP25°C/30min - 0.1MPaP-20°C/30min) are investigated as compared with that processed under high pressure processes (HPP, 100-500MPaP25°C/30min) and normal pressure immersion freezing process (IF, 0.1MPaP-20°C/30min). The results suggested that the treated PPO with the same enzyme activity may have various thermodynamic characteristics and conformations; Pressure-Factors play the main roles in the denaturation of the PPO during the HPF treatment, and Freezing-Factors can weak the effect of Pressure-Factors on PPO denaturation; The treated PPO may be transferred into a partially fold intermediate state.
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Affiliation(s)
- Lina Cheng
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Sericulture & Agri-Food Research Institute Guangdong Academy of Agricultural Sciences/Key Laboratory of Functional Foods, Ministry of Agriculture and Rural Affairs/Guangdong Key Laboratory of Agricultural Products Processing, Guangzhou 510610, China
| | - Zhiwei Zhu
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China
| | - Da-Wen Sun
- School of Food Science and Engineering, South China University of Technology, Guangzhou 510641, China; Academy of Contemporary Food Engineering, South China University of Technology, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Engineering and Technological Research Centre of Guangdong Province on Intelligent Sensing and Process Control of Cold Chain Foods, & Guangdong Province Engineering Laboratory for Intelligent Cold Chain Logistics Equipment for Agricultural Products, Guangzhou Higher Education Mega Centre, Guangzhou 510006, China; Food Refrigeration and Computerized Food Technology (FRCFT), Agriculture and Food Science Centre, University College Dublin, National University of Ireland, Belfield, Dublin 4, Ireland.
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24
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Han W, Hou M, He F, Zhang W, Shi B. Ecotoxicity and interacting mechanism of anionic surfactant sodium dodecyl sulfate (SDS) and its mixtures with nonionic surfactant fatty alcohol-polyoxyethlene ether (AEO). Aquat Toxicol 2020; 222:105467. [PMID: 32208300 DOI: 10.1016/j.aquatox.2020.105467] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2019] [Revised: 02/20/2020] [Accepted: 03/07/2020] [Indexed: 06/10/2023]
Abstract
This paper reports the proportion-dependent toxicity of binary surfactant mixtures containing anionic sodium dodecyl sulfate (SDS) and nonionic fatty alcohol-polyoxyethlene ether (AEO) toward Photobacterium phosphoreum. The crucial role of toxicity interactions was elucidated by spectroscopic probing the refolding of the unfolded bovine serum albumin (BSA) induced by SDS and theoretical calculating the interaction parameter of mixed surfactants based on Rubingh's model from the critical micelle concentrations. The SDS/AEO mixtures can be divided into two groups based on the toxicity response to the proportion of AEO in the mixtures: Group I contained low mass proportions of AEO, that is, SDS:AEO = 4:1, 3:1; Group II featured high AEO proportions, that is, SDS:AEO = 3:2, 1:1, 2:3, 1:4. The toxicity of SDS/AEO mixtures decreased with the enhanced proportion of AEO in Group I and then fluctuated slightly when the AEO proportion increased to that of Group II. The mixture with the mass ratio of 1:1 showed a slightly higher toxicity than the others in Group II. Scanning electron microscopy (SEM) images illustrated that the addition of AEO hindered the action of SDS against the cell membrane. Fluorescence measurement indicated that AEO could extract SDS molecules embedded in the BSA matrix, except for those bound to the highly active sites of BSA, and refold stepwise the unfolded protein. The results were in excellent analogy to the proportion-dependent toxicity of SDS/AEO mixture, indicating the formation of mixed micelles playing a key role. The interaction parameter further revealed that antagonism led to the mixture with equal mass ratio (1:1) showing higher toxicity than other mass ratios in Group II. These results can be useful for compounding SDS/AEO mixtures in application efficiently and eco-friendly.
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Affiliation(s)
- Weimo Han
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu, Sichuan, 610065, China; National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Mengchun Hou
- National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Faming He
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu, Sichuan, 610065, China; National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu, Sichuan, 610065, China
| | - Wenhua Zhang
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu, Sichuan, 610065, China; National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu, Sichuan, 610065, China.
| | - Bi Shi
- The Key Laboratory of Leather Chemistry and Engineering of Ministry of Education, Sichuan University, Chengdu, Sichuan, 610065, China; National Engineering Laboratory for Clean Technology of Leather Manufacture, Sichuan University, Chengdu, Sichuan, 610065, China
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Mehrvand J, Hayati Roodbari N, Hassani L, Jafarian V, Khalifeh K. An evolution-based designing and characterization of mutants of cyclomaltodextrinase: Molecular modeling and spectroscopic studies. Spectrochim Acta A Mol Biomol Spectrosc 2020; 230:118055. [PMID: 31955121 DOI: 10.1016/j.saa.2020.118055] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2019] [Revised: 01/05/2020] [Accepted: 01/09/2020] [Indexed: 06/10/2023]
Abstract
Cyclomaltodextrinase (CDase) is a member of the alpha-amylase family GH13, the subfamily GH13_20. In addition to CDase and neopullulanase, this subfamily also contains maltogenic amylase. They have common structural features, but different substrate specificity. In current work, a combination of bioinformatics and experimental tools were used for designing and constructions of single and double mutants of a new variant of CDase from Anoxybacillus flavithermus. Considering the evolutionary variable positions 123 and 127 at the dimer interface of subunits in the alpha-amylase family, these positions in CDase were modified and three mutants, including A123V, C127Q and A123V/C127Q were constructed. The tertiary structure of WT and mutants were made with the MODELLER program, and the phylogenetic tree of homologous protein sequences was built with selected programs in Phylip package. Enzyme kinetic studies revealed that the catalytic efficiency of mutants, especially double one, is lower than the WT enzyme. Heat-induced denaturation experiments were monitored by measuring the UV/Vis signal at 280 nm, and it was found that WT protein is structurally more stable at 25 °C. However, it is more susceptible to changes in temperature compared to the double mutant. It was concluded that the positions 123 and 127 at the dimeric interface of CDase, not only could affect the conformational stability; but also; the catalytic properties of the enzyme by setting up the active site configuration in the dimeric state.
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Affiliation(s)
- Jamshid Mehrvand
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Nasim Hayati Roodbari
- Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran
| | - Leila Hassani
- Department of Biological Sciences, Institute for Advanced Studies in Basic Sciences (IASBS), Zanjan, Iran
| | - Vahab Jafarian
- Department of Biology, Faculty of Sciences, University of Zanjan, Zanjan, Iran.
| | - Khosrow Khalifeh
- Department of Biology, Faculty of Sciences, University of Zanjan, Zanjan, Iran.
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Jia G, van den Berg F, Hao H, Liu H. Estimating the structure of sarcoplasmic proteins extracted from pork tenderloin thawed by a high-voltage electrostatic field. J Food Sci Technol 2020; 57:1574-1578. [PMID: 32180654 PMCID: PMC7054592 DOI: 10.1007/s13197-020-04253-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Revised: 12/05/2019] [Accepted: 01/09/2020] [Indexed: 06/10/2023]
Abstract
The application of high-voltage electrostatic field (HVEF) is a novel method of thawing. To determine if HVEF thawing could lead to sarcoplasmic proteins denaturation, and to provide a theoretical estimation of the structure of the sarcoplasmic proteins, pork tenderloin was thawed by traditional and HVEF methods. The results from protein solubility analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis, Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter showed that HVEF thawing did not result in more protein denaturation than those thawed under air or running water. From the principal component analysis of FTIR raw spectra (1700-1600 cm-1, Amide I region), we observed some separations of samples with different thawing treatments. It was found that the proportions of α-helix (1650-1640 cm-1 spectral bands in the original data) could lead to the differences on the PC2 axis of score plots.
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Affiliation(s)
- Guoliang Jia
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing, 100083 China
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083 China
- College of Biological Sciences and Technology, Beijing Forestry University, Beijing, China
| | - Frans van den Berg
- Department of Food Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Han Hao
- College of Economics and Business Administration, Beijing University of Posts and Telecommunications, Beijing, 100876 China
| | - Haijie Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, China Agricultural University, Beijing, 100083 China
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing, 100083 China
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Marshall L, Tarakanova A, Szarek P, Pierce DM. Cartilage and collagen mechanics under large-strain shear within in vivo and at supraphysiogical temperatures. J Mech Behav Biomed Mater 2020; 103:103595. [PMID: 32090923 DOI: 10.1016/j.jmbbm.2019.103595] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/13/2019] [Accepted: 12/10/2019] [Indexed: 11/28/2022]
Abstract
Human joints, particularly those of extremities, experience a significant range of temperatures in vivo. Joint temperature influences the mechanics of both joint and cartilage, and the mechanics of cartilage can affect the temperature of both joint and cartilage. Thermal treatments and tissue repairs, such as thermal chondroplasty, and ex vivo tissue engineering may also expose cartilage to supraphysiological temperatures. Furthermore, although cartilage undergoes principally compressive loads in vivo, shear strain plays a significant role at larger compressive strains. Thus, we aimed to determine whether and how the bulk mechanical responses of cartilage undergoing large-strain shear change (1) within the range of temperatures relevant in vivo, and (2) both during and after supraphysiological thermal treatments. We completed large-strain shear tests (10 and 15%) at four thermal conditions: 24∘C and 40∘C to span the in vivo range, and 70∘C and 24∘C repeated after 70∘C to explore mechanics during and after potential treatments. We calculated the bulk mechanical responses (strain-energy dissipation densities, peak-to-peak shear stresses, and peak-effective shear moduli) as of function of temperature and used statistical methods to probe significant differences. To probe the mechanisms underlying differences we assessed specimens, principally the type II collagen, with imaging (second harmonic generation and transmission electron microscopies, and histology) and assessed the temperature-dependent mechanics of type II collagen molecules within cartilage using steered molecular dynamics simulations. Our results suggest that the bulk mechanical responses of cartilage depend significantly on temperature both within the in vivo range and at supraphysiological temperatures, showing significant reductions in all mechanical measures with increasing temperature. Using imaging and simulations we determined that one underlying mechanism explaining our results may be changes in the molecular deformation profiles of collagen molecules versus temperature, likely compounded at larger length scales. These new insights into the mechanics of cartilage and collagen may suggest new treatment targets for damaged or osteoarthritic cartilage.
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Affiliation(s)
- Lauren Marshall
- Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Road, Unit 3139, Storrs, CT, 06269, USA
| | - Anna Tarakanova
- Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Road, Unit 3139, Storrs, CT, 06269, USA; Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Unit 3247, Storrs, CT, 06269, USA
| | - Phoebe Szarek
- Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Unit 3247, Storrs, CT, 06269, USA
| | - David M Pierce
- Department of Mechanical Engineering, University of Connecticut, 191 Auditorium Road, Unit 3139, Storrs, CT, 06269, USA; Department of Biomedical Engineering, University of Connecticut, 260 Glenbrook Road, Unit 3247, Storrs, CT, 06269, USA.
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Billard-Pomares T, Bleibtreu A, Walewski V, Dziri S, Barbat A, Zahar JR, Cruaud P, Carbonnelle E. Proposition of a safe Mycobacterium tuberculosis complex denaturation method that does not compromise the integrity of DNA for whole-genome sequencing. Tuberculosis (Edinb) 2019; 117:62-4. [PMID: 31378270 DOI: 10.1016/j.tube.2019.06.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2018] [Revised: 06/18/2019] [Accepted: 06/19/2019] [Indexed: 11/21/2022]
Abstract
Whole-genome sequencing plays now a leading role in epidemiologic studies of tuberculosis. DNA extraction of Mycobacterium tuberculosis complex (MTBC) requires complete inactivation of the strains, to be handled for further molecular procedures. In this study we compared two chloroform-based denaturation methods (one with a step of heat killing, one without) to a traditional heat inactivation method. Our results showed that 40% of the strains of MTBC treated by the traditional protocol resulted in a positive culture whereas no culture was observed with the two chloroform-based protocols. The DNA extracts obtained with chloroform-based protocols preparation were successfully used for whole-genome sequencing. We recommend inactivation with our rapid and efficient denaturation method using chloroform without heat killing which met our expectations and biosecurity requirements.
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Zhang Y, Wang Y, Li Y. Major cause of antibody artifact bands on non-reducing SDS-PAGE and methods for minimizing artifacts. Protein Expr Purif 2019; 164:105459. [PMID: 31344475 DOI: 10.1016/j.pep.2019.105459] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 07/17/2019] [Accepted: 07/22/2019] [Indexed: 11/23/2022]
Abstract
When monoclonal antibodies (mAbs) are analysed by non-reducing sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), method-induced artifacts are a frequent phenomenon. Previous studies suggested that incomplete denaturation and disulfide-bond scrambling are two main causes of artifact bands. Thus, in practice samples are normally heated and treated with alkylating agent iodoacetamide (IAM) before loading to promote denaturation and block free sulfhydryl groups, respectively. In this work, we further studied the major cause of artifact bands on non-reducing SDS-PAGE and ways of eliminating artifacts with two purified mAbs. In both cases, it was found that artifact bands on non-gradient Tris-glycine gels are mainly caused by incomplete denaturation under typical gel conditions. In general, heating minimizes artifact bands due to incomplete denaturation but it also generates some extra bands. Combining heating with IAM treatment achieved slightly better results than heating alone. As an alternative to heating, treating the samples with 8 M urea also allows close to complete denaturation of samples and thus minimizes artifact bands. In addition, we learned that untreated samples (samples that are not heated or treated with urea) may look different on Bis-Tris gel depending on gel composition (non-gradient vs. gradient) and the buffer used (MES vs. MOPS). In certain case, the apparent lack of artifact bands on gradient Bis-Tris gel may be in fact due to insufficient resolution. In conclusion, this study further confirmed that full-denaturation of sample is critical for minimizing/avoiding artifact bands on non-reducing SDS-PAGE.
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Hata H, Nishiyama M, Kitao A. Molecular dynamics simulation of proteins under high pressure: Structure, function and thermodynamics. Biochim Biophys Acta Gen Subj 2019; 1864:129395. [PMID: 31302180 DOI: 10.1016/j.bbagen.2019.07.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/03/2019] [Accepted: 07/08/2019] [Indexed: 12/17/2022]
Abstract
BACKGROUND Molecular dynamics (MD) simulation is well-recognized as a powerful tool to investigate protein structure, function, and thermodynamics. MD simulation is also used to investigate high pressure effects on proteins. For conducting better MD simulation under high pressure, the main issues to be addressed are: (i) protein force fields and water models were originally developed to reproduce experimental properties obtained at ambient pressure; and (ii) the timescale to observe the pressure effect is often much longer than that of conventional MD simulations. SCOPE OF REVIEW First, we describe recent developments in MD simulation methodologies for studying the high-pressure structure and dynamics of protein molecules. These developments include force fields for proteins and water molecules, and enhanced simulation techniques. Then, we summarize recent studies of MD simulations of proteins in water under high pressure. MAJOR CONCLUSIONS Recent MD simulations of proteins in solution under pressure have reproduced various phenomena identified by experiments using high pressure, such as hydration, water penetration, conformational change, helix stabilization, and molecular stiffening. GENERAL SIGNIFICANCE MD simulations demonstrate differences in the properties of proteins and water molecules between ambient and high-pressure conditions. Comparing the results obtained by MD calculations with those obtained experimentally could reveal the mechanism by which biological molecular machines work well in collaboration with water molecules.
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Affiliation(s)
- Hiroaki Hata
- School of Life Science and Technology, Tokyo Institute of Technology, Ookayama, 2-12-1 Meguro-ku, Tokyo 152-8550, Japan
| | - Masayoshi Nishiyama
- Department of Physics, Kindai University, 3-4-1 Kowakae, Higashiosaka, Osaka 577-8502, Japan
| | - Akio Kitao
- School of Life Science and Technology, Tokyo Institute of Technology, Ookayama, 2-12-1 Meguro-ku, Tokyo 152-8550, Japan.
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O'Neil PT, Machen AJ, Thompson JA, Wang W, Hoang QQ, Baldwin MR, Khar KR, Karanicolas J, Fisher MT. Constructing Kinetically Controlled Denaturation Isotherms of Folded Proteins Using Denaturant-Pulse Chaperonin Binding. Methods Mol Biol 2019; 1873:293-304. [PMID: 30341618 DOI: 10.1007/978-1-4939-8820-4_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Methods to assess the kinetic stability of proteins, particularly those that are aggregation prone, are very useful in establishing ligand induced stabilizing effects. Because aggregation prone proteins are by nature difficult to work with, most solution based methods are compromised by this inherent instability. Here, we describe a label-free method that examines the denaturation of immobilized proteins where the dynamic unfolded protein populations are captured and detected by chaperonin binding.
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Gao Q, Minobe E, Kameyama M, Xu J. Purification of insoluble GST-fused and GST-cleaved Cav1.2 channel fragment by denaturation and renaturation. Protein Expr Purif 2019; 160:7-10. [PMID: 30926461 DOI: 10.1016/j.pep.2019.03.013] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/14/2019] [Accepted: 03/24/2019] [Indexed: 11/25/2022]
Abstract
Both recombinant glutathione-S-transferase (GST)-fused and GST-cleaved fragments of an L-type voltage-gated Ca2+ channel (Cav1.2) are used frequently in GST pull-down assays to investigate the interactions between regulatory proteins and the Cav1.2 channel. However, GST-fused and GST-cleaved proximal C-terminal fragments of the guinea-pig cardiac Cav1.2 channel (CT1, amino acids 1509-1791) heterologously expressed in Escherichia coli (E. coli) are difficult to be recovered in a bioactive form because they are only poorly soluble. In this study, we developed a new method to solubilize and purify CT1. GST-CT1 expressed in E. coli was extracted and treated with an inclusion body solubilization and renaturation kit. Then, after adsorption to glutathione Sepharose beads, GST-CT1 was treated with protease to release CT1. However, the cleaved CT1 was insoluble and remained attached to the beads. Therefore, CT1 was treated again with the inclusion body solubilization and renaturation kit. Using this method, GST-CT1 and CT1 were purified with a high yield. GST pull-down experiments showed a dose-dependent interaction between GST-CT1 and calmodulin (CaM), and between GST-CaM and CT1, suggesting recovered bioactivity of GST-CT1 and CT1. This protocol may also be applied to purify other insoluble GST-fused proteins.
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Affiliation(s)
- Qinghua Gao
- Department of Physiology, Graduate School of Medical & Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Etsuko Minobe
- Department of Physiology, Graduate School of Medical & Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Masaki Kameyama
- Department of Physiology, Graduate School of Medical & Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan.
| | - Jianjun Xu
- Department of Physiology, Graduate School of Medical & Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan.
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Andrade IRAD, Cândido MJD, Pompeu RCFF, Feitosa TS, Bomfim MAD, Salles HO, Egito ASD. Inactivation of lectins from castor cake by alternative chemical compounds. Toxicon 2019; 160:47-54. [PMID: 30790577 DOI: 10.1016/j.toxicon.2019.02.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2018] [Accepted: 02/03/2019] [Indexed: 10/27/2022]
Abstract
Enabling the use of castor cake in animal feeding is an excellent alternative strategy to reduce feed costs. The cake is a by-product derived from the extraction of the castor oil by the biodiesel industry whose chemical composition is satisfactory despite the presence of antinutritional factors like toxic lectins, which require detoxification before it can be used as a dietary ingredient. The aim of the present study was to evaluate alternative chemical sources in the degradation and inactivation of ricin and Ricinus communis agglutinin (RCA), two lectins from castor cake. Ten chemical compounds were evaluated: sodium hydroxide, monodicalcium phosphate, dicalcium phosphate, calcium oxide, calcium hydroxide, calcitic limestone, magnesian limestone, urea, potassium chloride, and sodium chloride. Gel electrophoresis indicated 100% lectin degradation only in the cakes treated with 90 g sodium hydroxide and 2500 mL water per kg of cake. The hemagglutination assay was crucial to providing innocuousness to the treated cakes, with total absence of hemagglutinating activity observed in the castor cakes treated with 60 or 90 g sodium hydroxide in water volumes equal to or higher than 1500 mL/kg of castor cake and in the cakes treated with 90 g calcium oxide with 2500 or 3000 mL water/kg castor cake. Thus, though depending on the concentration of the chemical compound and on the volume of water per kilogram of treated cake, sodium hydroxide and calcium oxide showed to be promising chemical products for degradation and complete inactivation of the lectins present in castor cake to allow its use as an ingredient in animal diets.
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Affiliation(s)
- Igo Renan Albuquerque de Andrade
- Instituto Federal de Educação, Ciência e Tecnologia do Ceará/IFCE, Campus Crateús, Av. Geraldo Marques Barbosa, 567, 63708-260, Crateús, CE, Brazil.
| | - Magno José Duarte Cândido
- Universidade Federal do Ceará, Centro de Ciências Agrárias, Departamento de Zootecnia, Av. Mister Hull, 2977, Bl. 808, Pici Campus, 60440-554, Fortaleza, CE, Brazil.
| | | | - Tibério Sousa Feitosa
- Departamento de Zootecnia, ESALQ, Universidade de São Paulo, Avenida Pádua Dias, 11, 13418-900, Piracicaba, SP, Brazil
| | | | - Hévila Oliveira Salles
- Embrapa Caprinos e Ovinos, Estrada Sobral - Groaíras, Km 04, PO Box 71, 62010-970, Sobral, CE, Brazil
| | - Antonio Silvio do Egito
- Embrapa Caprinos e Ovinos/Núcleo Regional Nordeste, Rua Oswaldo Cruz, n° 1.143, Bairro Centenário, 58.428-095, Campina Grande, PB, Brazil.
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Ghosh S, Salama F, Dines M, Lahav A, Adir N. Biophysical and structural characterization of the small heat shock protein HspA from Thermosynechococcus vulcanus in 2 M urea. Biochim Biophys Acta Proteins Proteom 2019; 1867:442-452. [PMID: 30711645 DOI: 10.1016/j.bbapap.2018.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2018] [Revised: 11/29/2018] [Accepted: 12/11/2018] [Indexed: 10/27/2022]
Abstract
Small heat shock proteins (sHSPs) belong to the superfamily of molecular chaperones. They prevent aggregation of partially unfolded or misfolded client proteins, providing protection to organisms under stress conditions. Here, we report the biophysical and structural characterization of a small heat shock protein (HspA) from a thermophilic cyanobacterium Thermosynechococcus vulcanus in the presence of 2 M urea. HspA has been shown to be important for the protection of Photosystem II and the Phycobilisome antenna complex at elevated temperatures. Heterologously expressed HspA requires the presence of 1-2 M urea to maintain its solubility at concentrations required for most characterization methods. Spectroscopic studies reveal the presence of the β-sheet structure and intactness of the tertiary fold in HspA. In vitro assays show that the HspA maintains chaperone-like activity in protecting soluble proteins from thermal aggregation. Chromatography and electron microscopy show that the HspA exists as a mixture of oligomeric forms in the presence of 2 M urea. HspA was successfully crystallized only in the presence of 2 M urea. The crystal structure of HspA shows urea-induced loss of about 30% of the secondary structure without major alteration in the tertiary structure of the protein. The electron density maps reveal changes in the hydrogen bonding network which we attribute to the presence of urea. The crystal structure of HspA demonstrates a mixture of both direct interactions between urea and protein functionalities and interactions between urea and the surrounding solvent that indirectly affect the protein, which are in accordance with previously published studies.
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Affiliation(s)
- Sudeshna Ghosh
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Faris Salama
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Monica Dines
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Avital Lahav
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel
| | - Noam Adir
- Schulich Faculty of Chemistry, Technion - Israel Institute of Technology, Technion City, Haifa 32000, Israel.
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Weiss GL, Rainville JR, Zhao Q, Tasker JG. Purity and stability of the membrane-limited glucocorticoid receptor agonist dexamethasone-BSA. Steroids 2019; 142:2-5. [PMID: 28939328 PMCID: PMC5860924 DOI: 10.1016/j.steroids.2017.09.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Revised: 09/08/2017] [Accepted: 09/12/2017] [Indexed: 10/18/2022]
Abstract
Cellular effects of glucocorticoids can be separated into classical transcriptional regulation via activation of the canonical nuclear glucocorticoid receptor and rapid actions mediated by activation of one or more putative membrane-associated glucocorticoid receptors that regulate both transcriptional and non-transcriptional signaling. Dexamethasone-bovine serum albumin (Dex-BSA) is one of several membrane-limited steroid receptor agonists. Dex-BSA and other steroid conjugates such as corticosterone-, estradiol- and testosterone-BSA have been used to study rapid steroid effects initiated by putative membrane receptors. The purity and stability of the steroid-BSA conjugate is crucial, therefore, since any steroid that is not bound to or that dissociates from the BSA conjugate could penetrate into the intracellular compartment and confound the experiment. We used fluorine NMR to determine if free Dex could be detected in a commercially available Dex-BSA dissolved in H2O. Non-covalently bound Dex was detected in the Dex-BSA solution, but the level of free Dex remained constant over time and with increasing temperature, indicating that the free Dex was not a result of instability of the Dex-BSA conjugate. The free Dex was lost when the Dex-BSA was denatured and subjected to dialysis, which suggested that it was trapped in the Dex-BSA three-dimensional structure and not covalently bound to the BSA. The purified, renatured Dex-BSA retained its rapid activity, which confirmed that the observed effects of Dex-BSA are not caused by non-covalently-bound Dex. Therefore, the Dex contaminant found in the Dex-BSA solution is likely to be tightly, but non-covalently, bound to BSA, and the Dex-BSA activity remains membrane-limited. Our findings indicate that Dex-BSA remains a suitable membrane-restricted glucocorticoid receptor agonist, but suggest that denaturing purification is a useful control for the study of membrane-initiated steroid-BSA actions.
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Affiliation(s)
- Grant L Weiss
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA
| | - Jennifer R Rainville
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA
| | - Qi Zhao
- Department of Chemistry, Tulane University, New Orleans, LA, USA
| | - Jeffrey G Tasker
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA; Tulane Brain Institute, Tulane University, New Orleans, LA, USA.
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Gaspard SJ, Brodkorb A. The Use of High Performance Liquid Chromatography for the Characterization of the Unfolding and Aggregation of Dairy Proteins. Methods Mol Biol 2019; 2039:103-115. [PMID: 31342422 DOI: 10.1007/978-1-4939-9678-0_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
High-performance liquid chromatography (HPLC) is routinely used to identify and characterize proteins. HPLC can help to understand protein aggregation processes in dairy products, which are induced by common industrial processing steps such as heat treatment. In this chapter, three complementary chromatographic methods are described, which are based on the principles of size exclusion and reversed-phase chromatography. These methods are used to determine the degree of denaturation and aggregation of proteins, and estimate the molecular weight of these aggregates.
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Affiliation(s)
- Sophie Jeanne Gaspard
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland.,School of Food and Nutritional Sciences, University College Cork, Cork, Ireland
| | - André Brodkorb
- Teagasc Food Research Centre, Moorepark, Fermoy, Cork, Ireland.
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Floyd JA, Siska C, Clark RH, Kerwin BA, Shaver JM. Adapting the chemical unfolding assay for high-throughput protein screening using experimental and spectroscopic corrections. Anal Biochem 2018; 563:1-8. [PMID: 30236889 PMCID: PMC6226613 DOI: 10.1016/j.ab.2018.08.027] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Revised: 08/29/2018] [Accepted: 08/31/2018] [Indexed: 12/15/2022]
Abstract
The chemical unfolding (denaturation) assay can be used to calculate the change in the Gibbs free energy of unfolding, ΔG, and inflection point of unfolding, to collectively inform on molecule stability. Here, we evaluated methods for calculating the ΔG across 23 monoclonal antibody sequence variants. These methods are based on how the measured output (intrinsic fluorescence intensity) is treated, including utilizing (a) a single wavelength, (b) a ratio of two wavelengths, (c) a ratio of a single wavelength to an area, and (d) a scatter correction plus a ratio of a single wavelength to an area. When applied to the variants, the three ratio methods showed comparable results, with a similar pooled standard deviation for the ΔG calculation, while the single-wavelength method is shown as inadequate for the data in this study. However, when light scattering is introduced to simulated data, only the scatter-correction area normalization method proves robust. Using this method, common plate-based spectrophotometers found in many laboratories can be used for high-throughput screening of mAb variants and formulation stability studies.
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Affiliation(s)
- J Alaina Floyd
- Just Biotherapeutics, Inc., 401 Terry Ave N., Seattle, WA, 98109, USA
| | - Christine Siska
- Just Biotherapeutics, Inc., 401 Terry Ave N., Seattle, WA, 98109, USA
| | - Rutilio H Clark
- Just Biotherapeutics, Inc., 401 Terry Ave N., Seattle, WA, 98109, USA
| | - Bruce A Kerwin
- Just Biotherapeutics, Inc., 401 Terry Ave N., Seattle, WA, 98109, USA
| | - Jeremy M Shaver
- Just Biotherapeutics, Inc., 401 Terry Ave N., Seattle, WA, 98109, USA.
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Sil TB, Sahoo B, Garai K. Building, Characterization, and Applications of Cuvette-FCS in Denaturant-Induced Expansion of Globular and Disordered Proteins. Methods Enzymol 2018; 611:383-421. [PMID: 30471694 DOI: 10.1016/bs.mie.2018.08.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Fluorescence correlation spectroscopy (FCS) is a single-molecule sensitive technique with widespread applications in biophysics. However, conventional microscope-based FCS setups have limitations in performing certain experiments such as those requiring agitations such as stirring or heating, and those involving measurements in solvents with the mismatch of refractive indices. We have recently developed an FCS setup that is suitable for performing measurements inside regular cuvettes. The cuvette-FCS is suitable for performing single-molecule measurements in experiments that are regularly performed in spectrofluorometers but are generally avoided in microscope-based FCS. Here we describe building and characterization of the performance of the cuvette-FCS setup in detail. Finally, we have used a natively folded protein and an intrinsically disordered protein to demonstrate and describe how cuvette-FCS can be applied conveniently to measure urea-dependent expansion of hydrodynamic size of proteins.
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Ramakrishnan S, Ijäs H, Linko V, Keller A. Structural stability of DNA origami nanostructures under application-specific conditions. Comput Struct Biotechnol J 2018; 16:342-349. [PMID: 30305885 PMCID: PMC6169152 DOI: 10.1016/j.csbj.2018.09.002] [Citation(s) in RCA: 107] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2018] [Revised: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 12/21/2022] Open
Abstract
With the introduction of the DNA origami technique, it became possible to rapidly synthesize almost arbitrarily shaped molecular nanostructures at nearly stoichiometric yields. The technique furthermore provides absolute addressability in the sub-nm range, rendering DNA origami nanostructures highly attractive substrates for the controlled arrangement of functional species such as proteins, dyes, and nanoparticles. Consequently, DNAorigami nanostructures have found applications in numerous areas of fundamental and applied research, ranging from drug delivery to biosensing to plasmonics to inorganic materials synthesis. Since many of those applications rely on structurally intact, well-definedDNA origami shapes, the issue of DNA origami stability under numerous application-relevant environmental conditions has received increasing interest in the past few years. In this mini-review we discuss the structural stability, denaturation, and degradation of DNA origami nanostructures under different conditions relevant to the fields of biophysics and biochemistry, biomedicine, and materials science, and the methods to improve their stability for desired applications.
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Affiliation(s)
- Saminathan Ramakrishnan
- Technical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098 Paderborn, Germany
| | - Heini Ijäs
- Biohybrid Materials, Department of Bioproducts and Biosystems, Aalto University, P. O. Box 16100, FI-00076 Aalto, Finland
- University of Jyväskylä, Department of Biological and Environmental Science, P. O. Box 35, FI-40014 Jyväskylä, Finland
| | - Veikko Linko
- Technical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098 Paderborn, Germany
- Biohybrid Materials, Department of Bioproducts and Biosystems, Aalto University, P. O. Box 16100, FI-00076 Aalto, Finland
| | - Adrian Keller
- Technical and Macromolecular Chemistry, Paderborn University, Warburger Str. 100, 33098 Paderborn, Germany
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40
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Olsztyńska-Janus S, Kiełbowicz Z, Czarnecki MA. ATR-IR study of skin components: Lipids, proteins and water. Part II: Near infrared radiation effect. Spectrochim Acta A Mol Biomol Spectrosc 2018; 202:93-101. [PMID: 29778711 DOI: 10.1016/j.saa.2018.05.036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/03/2018] [Revised: 05/06/2018] [Accepted: 05/09/2018] [Indexed: 06/08/2023]
Abstract
Near infrared (NIR) radiation has been widely used in medicine and biomedical engineering. In spite of numerous studies the molecular mechanism of NIR radiation on biological systems has not been established as yet. The objective of this work was examination of the effect of NIR irradiation on the skin components. Modifications of lipid organization after NIR exposure vs. temperature (from 20 to 90 °C) have been investigated using Attenuated Total Reflectance Infrared (ATR-IR) spectroscopy. This work is a continuation of our previous studies on the temperature effect on skin components [1]. After NIR exposure a temperature shift of the phase transition from the orthorhombic to hexagonal packing (≈40 °C) has been observed. In contrast, the second phase transition temperature (≈70 °C) is almost invariable. The phase transitions in lipids were correlated with modifications of the structure of water and proteins. To our knowledge, for the first time the temperatures of the phase transitions after NIR exposure were investigated.
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Affiliation(s)
- S Olsztyńska-Janus
- Department of Biomedical Engineering, Wrocław University of Science and Technology, pl. Grunwaldzki 13, 50-370 Wroclaw, Poland.
| | - Z Kiełbowicz
- Department of Surgery the Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, pl. Grunwaldzki 51, 50-366 Wrocław, Poland
| | - M A Czarnecki
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
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Reddy D, Bhattacharya S, Jani V, Sonavane U, Joshi R, Gupta S. Biochemical and Biophysical Characterisation of Higher Oligomeric Structure of Rat Nucleosome Assembly Protein 1. Protein J 2018; 37:58-69. [PMID: 29209909 DOI: 10.1007/s10930-017-9751-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Nucleosome assembly protein 1 (NAP1) is a histone chaperone that exchanges histone H2A-H2B dimer from chromatin templates. Studies with yeast NAP1 (yNAP1) have revealed its existence as multiple oligomeric species in solution. Here, rat NAP1 (rNAP1), which is 98% identical to the human NAP1 (hNAP1) was used as a model to characterize the oligomeric structures of this protein in higher eukaryotes. Gel filtration chromatography and Dynamic light scattering of recombinant rNAP1 indicated that the protein exists as a complex mixture of multimeric species even at 500 mM ionic strength. The solution-state complexity remains unchanged even at higher ionic strengths. Equilibrium unfolding (ΔG 14.6 kcal mol- 1) shows that rNAP1, both dimeric and oligomeric, follow the two-state model of unfolding with no detectable intermediates. Homology modelling suggests that rat and yeast NAP1 share an overall similar structure with conserved domains. However, dissimilar substitutions like threonine and lysine with glycine in the β-hairpin involved in oligomerization, possibly leads to the observed differences in the oligomerization propensity of the two proteins. Molecular dynamic simulation (MDS) of the two structures also revealed that rNAP1 dimer is more stable owing to the extensive hydrogen bonding in comparison to yNAP1. Further, in vitro kinase assay showed that the phosphorylation of rNAP1 favors oligomerization with no effect on its histone binding capacity. Our results clearly suggest that there are differences in the in-solution behavior of rNAP1 compared to yNAP1 which may have in vivo functional implications for the regulation of these complexes during chromatin assembly and rearrangement.
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Affiliation(s)
- Divya Reddy
- Epigenetics and Chromatin Biology Group, Gupta Lab, Cancer Research Institute, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai, Maharashtra, 410210, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, Maharashtra, 400085, India
| | - Saikat Bhattacharya
- Epigenetics and Chromatin Biology Group, Gupta Lab, Cancer Research Institute, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai, Maharashtra, 410210, India.,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, Maharashtra, 400085, India.,Workman Lab, Stowers Institute for Medical Research, 1000 E 50th Street, Kansas City, MO, 64110, USA
| | - Vinod Jani
- Bioinformatics Group, Centre for Development of Advanced Computing (C-DAC), University of Pune Campus, Pune, Maharashtra, 411007, India
| | - Uddhavesh Sonavane
- Bioinformatics Group, Centre for Development of Advanced Computing (C-DAC), University of Pune Campus, Pune, Maharashtra, 411007, India
| | - Rajendra Joshi
- Bioinformatics Group, Centre for Development of Advanced Computing (C-DAC), University of Pune Campus, Pune, Maharashtra, 411007, India
| | - Sanjay Gupta
- Epigenetics and Chromatin Biology Group, Gupta Lab, Cancer Research Institute, Advanced Centre for Treatment, Research and Education in Cancer (ACTREC), Tata Memorial Centre, Kharghar, Navi Mumbai, Maharashtra, 410210, India. .,Homi Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai, Maharashtra, 400085, India.
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Mukhametzyanov TA, Sedov IA, Solomonov BN, Schick C. Fast scanning calorimetry of lysozyme unfolding at scanning rates from 5 K/min to 500,000 K/min. Biochim Biophys Acta Gen Subj 2018; 1862:2024-2030. [PMID: 29964144 DOI: 10.1016/j.bbagen.2018.06.019] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 06/22/2018] [Accepted: 06/26/2018] [Indexed: 10/28/2022]
Abstract
BACKGROUND Protein denaturation is often studied using differential scanning calorimetry (DSC). However, conventional instruments are limited in the temperature scanning rate available. Fast scanning calorimetry (FSC) provides an ability to study processes at much higher rates while using extremely small sample masses [ng]. This makes it a very interesting technique for protein investigation. METHODS A combination of conventional DSC and fast scanning calorimeters was used to study denaturation of lysozyme dissolved in glycerol. Glycerol was chosen as a solvent to prevent evaporation from the micro-sized samples of the fast scanning calorimeter. RESULTS The lysozyme denaturation temperatures in the range of scanning rates from 5 K/min to ca. 500,000 K/min follow the Arrhenius law. The experimental results for FSC and conventional DSC fall into two distinct clusters in a Kissinger plot, which are well approximated by two parallel straight lines. CONCLUSIONS The transition temperatures for the unfolding process measured on fast scanning calorimetry sensor are significantly lower than what could be expected from the results of conventional DSC using extrapolation to high scanning rates. Evidence for the influence of the relative surface area on the unfolding temperature was found. GENERAL SIGNIFICANCE For the first time, fast scanning calorimetry was employed to study protein denaturation with a range of temperature scanning rates of 5 orders of magnitude. Decreased thermal stability of the micro-sized samples on the fast scanning calorimeter raise caution over using bulk solution thermal stability data of proteins for applications where micro-sized dispersed protein solutions are used, e.g., spray drying.
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Affiliation(s)
| | - Igor A Sedov
- Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russian Federation
| | - Boris N Solomonov
- Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russian Federation
| | - Christoph Schick
- Kazan Federal University, 18 Kremlyovskaya Street, Kazan 420008, Russian Federation; University of Rostock, Institute of Physics, Albert-Einstein-Str. 23-24, 18051 Rostock, Germany
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43
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Baron GS, Raymond GJ. Immunodetection of PrP Sc Using Western Immunoblotting Techniques. Methods Mol Biol 2017; 1658:51-66. [PMID: 28861782 DOI: 10.1007/978-1-4939-7244-9_5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
Abstract
Western immunoblotting is a workhorse technique used in the prion field to analyze disease-associated forms of the prion protein, termed PrPSc. The biochemical stability of PrPSc aggregates combined with the increased resistance of prion infectivity to inactivation by various treatments that inactivate most other pathogens complicates the use of Western immunoblotting as a means to characterize PrPSc samples. In this chapter, we describe a method for Western immunoblot analysis of PrPSc with an emphasis on precautions to address the biochemical and biosafety considerations associated with this procedure.
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Olsztyńska-Janus S, Pietruszka A, Kiełbowicz Z, Czarnecki MA. ATR-IR study of skin components: Lipids, proteins and water. Part I: Temperature effect. Spectrochim Acta A Mol Biomol Spectrosc 2018; 188:37-49. [PMID: 28689077 DOI: 10.1016/j.saa.2017.07.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2017] [Revised: 06/30/2017] [Accepted: 07/01/2017] [Indexed: 06/07/2023]
Abstract
In this work we report the studies of the effect of temperature on skin components, such as lipids, proteins and water. Modifications of lipids structure induced by increasing temperature (from 20 to 90°C) have been studied using ATR-IR (Attenuated Total Reflectance Infrared) spectroscopy, which is a powerful tool for characterization of the molecular structure and properties of tissues, such as skin. Due to the small depth of penetration (0.6-5.6μm), ATR-IR spectroscopy probes only the outermost layer of the skin, i.e. the stratum corneum (SC). The assignment of main spectral features of skin components allows for the determination of phase transitions from the temperature dependencies of band intensities [e.g. νas(CH2) and νs(CH2)]. The phase transitions were determined by using two methods: the first one was based on the first derivative of the Boltzmann function and the second one employed tangent lines of sigmoidal, aforementioned dependencies. The phase transitions in lipids were correlated with modifications of the structure of water and proteins.
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Affiliation(s)
- S Olsztyńska-Janus
- Department of Biomedical Engineering, Wrocław University of Science and Technology, pl. Grunwaldzki 13, 50-370 Wrocław, Poland.
| | - A Pietruszka
- Department of Biomedical Engineering, Wrocław University of Science and Technology, pl. Grunwaldzki 13, 50-370 Wrocław, Poland
| | - Z Kiełbowicz
- Department of Surgery the Faculty of Veterinary Medicine, Wrocław University of Environmental and Life Sciences, pl. Grunwaldzki 51, 50-366 Wrocław, Poland
| | - M A Czarnecki
- Faculty of Chemistry, University of Wrocław, F. Joliot-Curie 14, 50-383 Wrocław, Poland
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45
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Saoudi O, Ghaouar N, Ben Salah S, Othman T. Denaturation process of laccase in various media by refractive index measurements. Biochem Biophys Rep 2017; 11:19-26. [PMID: 28955763 PMCID: PMC5614694 DOI: 10.1016/j.bbrep.2017.05.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 01/24/2017] [Accepted: 05/25/2017] [Indexed: 11/05/2022] Open
Abstract
In this work, we are interested in the denaturation process of a laccase from Tramates versicolor via the determination of the refractive index, the refractive index increment and the specific volume in various media. The measurements were carried out using an Abbe refractometer. We have shown that the refractive index increment values obtained from the slope of the variation of the refractive index vs. Concentration are outside the range refractive index increments of proteins. To correct the results, we have followed the theoretical predictions based on the knowledge of the protein refractive index from its amino acids composition. The denaturation process was studied by calculating the specific volume variation where its determination was related to the Gladstone-Dale and the Lorentz-Lorentz models. Refractive index measurements to follow the denaturation process in various medium. The denaturation process was studied by using the Gladstone-Dale and the Lorentz-Lorentz models. [Morph][F] denatures laccase faster than [pyrr][F].
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Affiliation(s)
- O Saoudi
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, 2092 Tunis, Tunisia
| | - N Ghaouar
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, 2092 Tunis, Tunisia.,Université de Carthage, Institut National des Sciences Appliquées et de Technologie, Centre Urbain Nord, BP. 676, Tunis, Tunisia
| | - S Ben Salah
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, 2092 Tunis, Tunisia
| | - T Othman
- Université de Tunis El Manar, Faculté des Sciences de Tunis, Laboratoire de Physique de la Matière Molle et de la Modélisation Electromagnétique, 2092 Tunis, Tunisia
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Khan NM, Ahmad I, Ansari MY, Haqqi TM. Wogonin, a natural flavonoid, intercalates with genomic DNA and exhibits protective effects in IL-1β stimulated osteoarthritis chondrocytes. Chem Biol Interact 2017; 274:13-23. [PMID: 28688942 PMCID: PMC5548605 DOI: 10.1016/j.cbi.2017.06.025] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 06/02/2017] [Accepted: 06/22/2017] [Indexed: 11/18/2022]
Abstract
Wogonin has recently been shown to possess anti-inflammatory and chondroprotective properties and is of considerable interest due to its broad pharmacological activities. The present study highlights that Wogonin binds DNA and exerts chondroprotective effects in vitro. Wogonin showed strong binding with chondrocytes genomic DNA in vitro. The mode of binding of Wogonin to genomic-DNA was assessed by competing Wogonin with EtBr or DAPI, known DNA intercalator and a minor groove binder, respectively. EtBr fluorescence reduced significantly with increase in Wogonin concentration suggesting possible DNA intercalation of Wogonin. Further, in silico molecular docking of Wogonin on mammalian DNA also indicated possible intercalation of Wogonin with DNA. The denaturation and FRET studies revealed that Wogonin prevents denaturation of DNA strands and provide stability to genomic DNA against a variety of chemical denaturants. The cellular uptake study showed that Wogonin enters osteoarthritis chondrocytes and was mainly localized in the nucleus. Wogonin treatment to OA chondrocytes protects the fragmentation of genomic DNA in response to IL-1β as evaluated by DNA ladder and TUNEL assay. Treatment of chondrocytes with Wogonin resulted in significant suppression of IL-1β-mediated induction of ROS. Further, Wogonin exhibited protective potential through potent suppression of extrinsic and intrinsic apoptotic pathways and induction of anti-apoptotic proteins in IL-1β-stimulated osteoarthritis chondrocytes. Our data thus suggest that DNA intercalation by Wogonin may result in the stabilization of genomic DNA leading to protective activity.
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Affiliation(s)
- Nazir M Khan
- Department of Anatomy & Neurobiology, Northeast Ohio Medical University, 4209 St Rt 44, Rootstown, OH 44272, USA
| | - Imran Ahmad
- Department of Anatomy & Neurobiology, Northeast Ohio Medical University, 4209 St Rt 44, Rootstown, OH 44272, USA
| | - Mohammad Y Ansari
- Department of Anatomy & Neurobiology, Northeast Ohio Medical University, 4209 St Rt 44, Rootstown, OH 44272, USA
| | - Tariq M Haqqi
- Department of Anatomy & Neurobiology, Northeast Ohio Medical University, 4209 St Rt 44, Rootstown, OH 44272, USA.
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Hsein H, Garrait G, Mumin MA, Beyssac E, Hoffart V. Atomization of denatured whey proteins as a novel and simple way to improve oral drug delivery system properties. Int J Biol Macromol 2017; 105:801-9. [PMID: 28732731 DOI: 10.1016/j.ijbiomac.2017.07.114] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Revised: 06/14/2017] [Accepted: 07/17/2017] [Indexed: 01/17/2023]
Abstract
In the sphere of drug delivery, denatured whey protein (DWP) has in recent times gained press. However, to date, no scalable and affordable dosage form has been developed. The objective of our study was to evaluate the potential use of spray-dried DWP as a ready to use excipient for oral drug delivery. Therefore, solid state, FTIR spectra and wettability were studied. Dissolution, mucoadhesion and the effect on paracellular permeability were also evaluated. The spray-dried DWP particles were spherical with 4μm mean diameter. Further, relative to native WP, the spray-dried DWP particles bore reduced wettability, and their structure was characterized by the exposure of a high amount of free thiol and by the formation of intermolecular β-sheets. The DWP powders were mucoadhesive, enzymatic inhibitors, biocompatible and they induced the opening of tight junctions. Our study shows great potential for the use of spray-drying as a technique to modify the dissolution rate of drugs and enhance the oral bioavailability of molecules. That is, the use of spray drying as a single step ready to use DWP excipient.
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Murphy RW, Farkas BE, Jones OG. Effect of crosslinking on the physical and chemical properties of β-lactoglobulin (Blg) microgels. J Colloid Interface Sci 2017; 505:736-44. [PMID: 28662476 DOI: 10.1016/j.jcis.2017.06.061] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/18/2017] [Indexed: 12/21/2022]
Abstract
HYPOTHESIS Microgels assembled from the protein β-lactoglobulin are colloidal structures with potential applications in food materials. Modifying the internal crosslinking within these microgels using enzymatic or chemical treatments should affect dissolution, swelling, and viscous attributes under strongly solvating conditions. EXPERIMENTS Microgels were treated with citric acid, glutaraldehyde and transglutaminase to induce cross-linking or with tris(2-carboxyethyl)phosphine to reduce disulfide linkages. Change in hydrodynamic particle size due to acidic pH, alkaline pH, ionic strength, osmolyte concentration, ethanol, urea, sodium dodecyl sulfate, and reducing agents was evaluated by light scattering measurements. Changes in microgel nanomechanical properties were evaluated via force spectroscopic measurements in water. FINDINGS Average microgel size increased ∼20% in alkaline pH and with ethanol contents above 10%, and decreased ∼20% with sucrose contents above 10%. Cross-linking by glutaraldehyde and transglutaminase prevented size increases in alkaline pH. Microgel plasticity and elastic modulus were unaffected by treatments. Microgels treated with glutaraldehyde were found to have much greater stability to urea, sodium dodecyl sulfate, and reducing agents when compared to other samples. Even without cross-linking, microgels remained stable against precipitation and dissolution over a wide range conditions, indicating their broad utility as colloidal stabilizers, texture modifiers or controlled release agents in food or other applications.
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Abstract
Reducing the time taken to run qPCR assays on today’s qPCR cyclers is rather straightforward and requires no specialised reagents or instruments. As the first article in a new series of short technical reports, I demonstrate that it is possible to reduce significantly both denaturation temperatures and cycling times, whilst retaining sensitivity and specificity of the original qPCR conditions.
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Affiliation(s)
- Stephen A Bustin
- Faculty of Medical Science, Postgraduate Medical Institute, Anglia Ruskin University, Chelmsford CM1 1SQ, UK
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50
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Shubin VV, Terekhova IV, Bolychevtseva YV, El-Mohsnawy E, Rögner M, Mäntele W, Kopczak MJ, Džafić E. Thermostability of photosystem I trimers and monomers from the cyanobacterium Thermosynechococcus elongatus. Spectrochim Acta A Mol Biomol Spectrosc 2017; 179:17-22. [PMID: 28213141 DOI: 10.1016/j.saa.2017.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2016] [Revised: 01/30/2017] [Accepted: 02/04/2017] [Indexed: 06/06/2023]
Abstract
The performance of solar energy conversion into alternative energy sources in artificial systems highly depends on the thermostability of photosystem I (PSI) complexes Terasaki et al. (2007), Iwuchukwu et al. (2010), Kothe et al. (2013) . To assess the thermostability of PSI complexes from the thermophilic cyanobacterium Thermosynechococcus elongatus heating induced perturbations on the level of secondary structure of the proteins were studied. Changes were monitored by Fourier transform infrared (FT-IR) spectra in the mid-IR region upon slow heating (1°C per minute) of samples in D2O phosphate buffer (pD 7.4) from 20°C to 100°C. These spectra showed distinct changes in the Amide I region of PSI complexes as a function of the rising temperature. Absorbance at the Amide I maximum of PSI monomers (centered around 1653cm-1), gradually dropped in two temperature intervals, i.e. 60-75 and 80-90°C. In contrast, absorbance at the Amide I maximum of PSI trimers (around 1656cm-1) dropped only in one temperature interval 80-95°C. The thermal profile of the spectral shift of α-helices bands in the region 1656-1642cm-1 confirms the same two temperature intervals for PSI monomers and only one interval for trimers. Apparently, the observed absorbance changes at the Amide I maximum during heating of PSI monomers and trimers are caused by deformation and unfolding of α-helices. The absence of absorbance changes in the interval of 20-65°C in PSI trimers is probably caused by a greater stability of protein secondary structure as compared to that in monomers. Upon heating above 80°C a large part of α-helices both in trimers and monomers converts to unordered and aggregated structures. Spectral changes of PSI trimers and monomers heated up to 100°C are irreversible due to protein denaturation and non-specific aggregation of complexes leading to new absorption bands at 1618-1620cm-1. We propose that monomers shield the denaturation sensitive sides at the monomer/monomer interface within a trimer, making the oligomeric structure more stable against thermal stress.
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Affiliation(s)
- Vladimir V Shubin
- Baсh Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld.2, Leninsky Ave., Moscow 119071, Russia
| | - Irina V Terekhova
- Baсh Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld.2, Leninsky Ave., Moscow 119071, Russia.
| | - Yulia V Bolychevtseva
- Baсh Institute of Biochemistry, Research Center of Biotechnology of the Russian Academy of Sciences, 33, bld.2, Leninsky Ave., Moscow 119071, Russia
| | - Eithar El-Mohsnawy
- Biochemie der Pflanzen, Ruhr Universität Bochum, 44780 Bochum, Germany; Botany Department, Faculty of Science, Kafrelsheikh University, 33511 Kafrelsheikh, Egypt
| | - Matthias Rögner
- Biochemie der Pflanzen, Ruhr Universität Bochum, 44780 Bochum, Germany
| | - Werner Mäntele
- Institut für Biophysik, J.W. Goethe Universität Frankfurt, 60438 Frankfurt, Germany
| | - Marta J Kopczak
- Biochemie der Pflanzen, Ruhr Universität Bochum, 44780 Bochum, Germany
| | - Enela Džafić
- Institut für Biophysik, J.W. Goethe Universität Frankfurt, 60438 Frankfurt, Germany
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