1
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Meng X, Wu Y, Tang W, Zhou L, Liu W, Liu C, Prakash S, Zhang Y, Zhong J. Comparison and analysis of mechanism of β-lactoglobulin self-assembled gel carriers formed by different gelation methods. Food Chem 2024; 442:138414. [PMID: 38237299 DOI: 10.1016/j.foodchem.2024.138414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/07/2023] [Accepted: 01/09/2024] [Indexed: 02/15/2024]
Abstract
Based on the findings of our previous studies, a comprehensive comparative investigation of the quality and formation mechanism of gels obtained from protein self-assemblies induced by different methods is necessary. Self-assembled heat-induced gels had higher gel mechanical strength, and hydrophobic interactions played a greater role. Whether or not heat treatment was used to induce gel formation may play a more important role than the effect of divalent cations on gel formation. Hydrogen bonds played an important role in all gels formed using different gelation methods. Furthermore, Self-assembled cold-induced gels were considered to can load bioactive substances with different hydrophilicity properties due to the high water-holding capacity and the smooth, dense microstructure. Therefore, β-lactoglobulin fibrous and worm-like self-assembled cold-induced gels as a delivery material for hydrophilic bioactive substances (epigallocatechin gallate, vitamin B2) and amphiphilic bioactive substance (naringenin), with good encapsulation efficiency (91.92 %, 97.08 %, 96.72 %, 96.52 %, 98.94 %, 97.41 %, respectively) and slow-release performance.
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Affiliation(s)
- Xiaolin Meng
- State Key Laboratory of Food Science and Resources, Nanchang University, No 235, Nanjing East Road, Nanchang, Jiangxi 330047, China
| | - Ying Wu
- State Key Laboratory of Food Science and Resources, Nanchang University, No 235, Nanjing East Road, Nanchang, Jiangxi 330047, China
| | - Wangruiqi Tang
- State Key Laboratory of Food Science and Resources, Nanchang University, No 235, Nanjing East Road, Nanchang, Jiangxi 330047, China
| | - Lei Zhou
- State Key Laboratory of Food Science and Resources, Nanchang University, No 235, Nanjing East Road, Nanchang, Jiangxi 330047, China
| | - Wei Liu
- State Key Laboratory of Food Science and Resources, Nanchang University, No 235, Nanjing East Road, Nanchang, Jiangxi 330047, China
| | - Chengmei Liu
- State Key Laboratory of Food Science and Resources, Nanchang University, No 235, Nanjing East Road, Nanchang, Jiangxi 330047, China
| | - Sangeeta Prakash
- School of Agriculture and Food Sustainability, The University of Queensland, St. Lucia, Brisbane, QLD 4072, Australia
| | - Yanjun Zhang
- A Spice and Beverage Research Institute, Chinese Academy of Tropical Agricultural Science, Wanning, 571533 Hainan, China.
| | - Junzhen Zhong
- State Key Laboratory of Food Science and Resources, Nanchang University, No 235, Nanjing East Road, Nanchang, Jiangxi 330047, China.
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2
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Pham PC, Taylor M, Nguyen GTH, Beltran J, Bennett JL, Ho J, Donald WA. Binding of Per- and Polyfluoroalkyl Substances to β-Lactoglobulin from Bovine Milk. Chem Res Toxicol 2024; 37:757-770. [PMID: 38625865 DOI: 10.1021/acs.chemrestox.4c00021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2024]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are known for their high environmental persistence and potential toxicity. The presence of PFAS has been reported in many dairy products. However, the mechanisms underlying the accumulation of PFAS in these products remain unclear. Here, we used native mass spectrometry and molecular dynamics simulations to probe the interactions between 19 PFAS of environmental concern and two isoforms of the major bovine whey protein β-lactoglobulin (β-LG). We observed that six of these PFAS bound to both protein isoforms with low- to mid-micromolar dissociation constants. Based on quantitative, competitive binding experiments with endogenous ligands, PFAS can bind orthosterically and preferentially to β-LG's hydrophobic ligand-binding calyx. β-Cyclodextrin can also suppress binding of PFAS to β-LG owing to the ability of β-cyclodextrin to directly sequester PFAS from solution. This research sheds light on PFAS-β-LG binding, suggesting that such interactions could impact lipid-fatty acid transport in bovine mammary glands at high PFAS concentrations. Furthermore, our results highlight the potential use of β-cyclodextrin in mitigating PFAS binding, providing insights toward the development of strategies to reduce PFAS accumulation in dairy products and other biological systems.
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Affiliation(s)
- P Chi Pham
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Mackenzie Taylor
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Giang T H Nguyen
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Jeunesse Beltran
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Jack L Bennett
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - Junming Ho
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
| | - William A Donald
- School of Chemistry, University of New South Wales, Sydney, New South Wales 2052, Australia
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3
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Al-Shabib NA, Khan JM, Malik A, AlAmri A, Rehman MT, AlAjmi MF, Husain FM. Integrated spectroscopic and computational analyses unravel the molecular interaction of pesticide azinphos-methyl with bovine beta-lactoglobulin. J Mol Recognit 2024:e3086. [PMID: 38686702 DOI: 10.1002/jmr.3086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2023] [Revised: 03/25/2024] [Accepted: 04/17/2024] [Indexed: 05/02/2024]
Abstract
Organophosphorus are typically hazardous chemicals used in the pharmaceutical, agricultural, and other industries. They pose a serious risk to human life and can be fatal upon direct exposure. Hence, studying the interaction between such compounds with proteins is crucial for environmental, health, and food safety. In this study, we investigated the interaction mechanism between azinphos-methyl (AZM) and β-lactoglobulin (BLG) at pH 7.4 using a combination of biophysical techniques. Intrinsic fluorescence investigations revealed that BLG fluorescence was quenched in the presence of increasing AZM concentrations. The quenching mechanism was identified as static, as evidenced by a decrease in the fluorescence quenching constant (1.25 × 104, 1.18 × 104, and 0.86 × 104 M-1) with an increase in temperatures. Thermodynamic calculations (ΔH > 0; ΔS > 0) affirmed the formation of a complex between AZM and BLG through hydrophobic interactions. The BLG's secondary structure was found to be increased due to AZM interaction. Ultraviolet -visible spectroscopy data showed alterations in BLG conformation in the presence of AZM. Molecular docking highlighted the significant role of hydrophobic interactions involving residues such as Val43, Ile56, Ile71, Val92, Phe105, and Met107 in the binding between BLG and AZM. A docking energy of -6.9 kcal mol-1, and binding affinity of 1.15 × 105 M-1 suggest spontaneous interaction between AZM and BLG with moderate to high affinity. These findings underscore the potential health risks associated with the entry of AZM into the food chain, emphasizing the need for further consideration of its impact on human health.
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Affiliation(s)
- Nasser Abdulatif Al-Shabib
- Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Javed Masood Khan
- Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia
| | - Ajamaluddin Malik
- Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Abdulaziz AlAmri
- Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
| | - Md Tabish Rehman
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Mohamed F AlAjmi
- Department of Pharmacognosy, College of Pharmacy, King Saud University, Riyadh, Saudi Arabia
| | - Fohad Mabood Husain
- Department of Food Science and Nutrition, Faculty of Food and Agricultural Sciences, King Saud University, Riyadh, Saudi Arabia
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4
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Liu J, Engholm-Keller K, Poojary MM, Bevilacqua M, Andersen ML, Lund MN. Reactivity and mechanism of the reactions of 4-methylbenzoquinone with amino acid residues in β-lactoglobulin: A kinetic and product investigation. Food Chem 2024; 434:137473. [PMID: 37738814 DOI: 10.1016/j.foodchem.2023.137473] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Revised: 06/29/2023] [Accepted: 09/11/2023] [Indexed: 09/24/2023]
Abstract
Quinones, produced by the oxidation of phenolic compounds, covalently bind to nucleophilic groups on amino acids or proteins. In this study, the reactions of 4-methylbenzoquinone (4MBQ) with β-lactoglobulin (β-LG) and amino acids at neutral pH were investigated. LC-MS analysis revealed that Cys121 was likely the most modified residue in β-LG. Identification of reaction products by LC-MS/MS showed that Michael addition occurred in all reactions with amino acids tested. The formation of Schiff base and a di-adduct was found in His and Trp samples. Apparent second-order rate constants (k2) were determined at 25 °C and pH 7.0 by stopped-flow spectrophotometry. The rate of reactions decreased in the order: β-LG > His > Trp > Arg > Nα-acetyl His > Nα-acetyl Arg > Nα-acetyl Trp. The rate constants correlated with the pKa values of the amino acids, showing that the amount of unprotonated amine is the major factor determining the reactivity.
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Affiliation(s)
- Jingyuan Liu
- Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Kasper Engholm-Keller
- Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Mahesha M Poojary
- Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Marta Bevilacqua
- Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Mogens L Andersen
- Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark
| | - Marianne N Lund
- Department of Food Science, Faculty of Science, University of Copenhagen, Rolighedsvej 26, 1958 Frederiksberg C, Denmark; Department of Biomedical Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200 Copenhagen N, Denmark.
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5
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Bonarek P, Mularczyk D, Loch JI, Kurpiewska K, Dziedzicka-Wasylewska M. β-Lactoglobulin variants as potential carriers of pramoxine: Comprehensive structural and biophysical studies. J Mol Recognit 2023; 36:e3052. [PMID: 37610054 DOI: 10.1002/jmr.3052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Revised: 07/24/2023] [Accepted: 08/07/2023] [Indexed: 08/24/2023]
Abstract
β-Lactoglobulin (BLG) is a member of the lipocalin family. As other proteins from this group, BLG can be modified to bind specifically compounds of medical interests. The aim of this study was to evaluate the role of two mutations, L39Y and L58F, in the binding of topical anesthetic pramoxine (PRM) to β-lactoglobulin. Circular dichroism spectroscopy, isothermal titration calorimetry (ITC), and X-ray crystallography were used to understand the mechanisms of BLG-PRM interactions. Studies were performed for three new BLG mutants: L39Y, L58F, and L39Y/L58F. ITC measurements indicated a significant increase in the affinity to the PRM of variants L58F and L39Y. Measurements taken for the double mutant L39Y/L58F showed the additivity of two mutations leading to about 80-fold increase in the affinity to PRM in comparison to natural protein BLG from bovine milk. The determined crystal structures revealed that pramoxine is accommodated in the β-barrel interior of BLG mutants and stabilized by hydrophobic interactions. The observed additive effect of two mutations on drug binding opens the possibility for further designing of new BLG variants with high affinity to selected drugs.
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Affiliation(s)
- Piotr Bonarek
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Physical Biochemistry, Jagiellonian University, Kraków, Poland
| | - Dorota Mularczyk
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Physical Biochemistry, Jagiellonian University, Kraków, Poland
| | - Joanna I Loch
- Faculty of Chemistry, Department of Crystal Chemistry and Crystal Physics, Jagiellonian University, Kraków, Poland
| | - Katarzyna Kurpiewska
- Faculty of Chemistry, Department of Crystal Chemistry and Crystal Physics, Jagiellonian University, Kraków, Poland
| | - Marta Dziedzicka-Wasylewska
- Faculty of Biochemistry, Biophysics and Biotechnology, Department of Physical Biochemistry, Jagiellonian University, Kraków, Poland
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6
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Christoffer C, Kihara D. Modeling protein-nucleic acid complexes with extremely large conformational changes using Flex-LZerD. Proteomics 2023; 23:e2200322. [PMID: 36529945 PMCID: PMC10448949 DOI: 10.1002/pmic.202200322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Revised: 12/08/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022]
Abstract
Proteins and nucleic acids are key components in many processes in living cells, and interactions between proteins and nucleic acids are often crucial pathway components. In many cases, large flexibility of proteins as they interact with nucleic acids is key to their function. To understand the mechanisms of these processes, it is necessary to consider the 3D atomic structures of such protein-nucleic acid complexes. When such structures are not yet experimentally determined, protein docking can be used to computationally generate useful structure models. However, such docking has long had the limitation that the consideration of flexibility is usually limited to small movements or to small structures. We previously developed a method of flexible protein docking which could model ordered proteins which undergo large-scale conformational changes, which we also showed was compatible with nucleic acids. Here, we elaborate on the ability of that pipeline, Flex-LZerD, to model specifically interactions between proteins and nucleic acids, and demonstrate that Flex-LZerD can model more interactions and types of conformational change than previously shown.
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Affiliation(s)
- Charles Christoffer
- Department of Computer Science, Purdue University, West Lafayette, Indiana, USA
| | - Daisuke Kihara
- Department of Computer Science, Purdue University, West Lafayette, Indiana, USA
- Department of Biological Sciences, Purdue University, West Lafayette, Indiana, USA
- Purdue University Center for Cancer Research, Purdue University, West Lafayette, Indiana, USA
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7
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Börsig A, Konar N, Dalabasmaz S. A model study on the site-specificity of (-)-epicatechin-induced reactions in β-lactoglobulin by high-resolution mass spectrometry in combination with bioinformatics. Food Chem 2023; 408:135242. [PMID: 36566544 DOI: 10.1016/j.foodchem.2022.135242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 11/23/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022]
Abstract
Polyphenol-protein reactions in model solutions of β-lactoglobulin (β-LG) incubated with (-)-epicatechin at 37 °C and 60 °C were monitored by microLC-timsTOF Pro-MS/MS combined with bioinformatics strategies. The addition of (-)-epicatechin to the model solutions resulted in changes in tryptic peptide profiles. Covalent bond formation between (-)-epicatechin o-quinones and β-LG was identified for the residues S27, S30, K60, C66, K69, and C160, with C160 being the predominant binding site. Furthermore, the incubation of β-LG with (-)-epicatechin significantly promoted oxidation, especially for the residues M7 and M24. The reaction of monomeric (-)-epicatechino-quinone at C160 was also identified in the milk chocolate sample. The adaptation of this study by extending the scope of the reaction products offers significant potential for comprehensive food profiling strategies.
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Affiliation(s)
- Amelie Börsig
- Food Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany.
| | - Nevzat Konar
- Department of Food Engineering, Eskisehir Osmangazi University, 26160 Eskisehir, Turkey.
| | - Sevim Dalabasmaz
- Food Chemistry, Department of Chemistry and Pharmacy, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Nikolaus-Fiebiger-Straße 10, 91058 Erlangen, Germany.
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8
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Mckerchar HJ, Lento C, Bennie RZ, Crowther JM, Dolamore F, Dyer JM, Clerens S, Mercadante D, Wilson DJ, Dobson RCJ. The protein dynamics of bovine and caprine β-lactoglobulin differ as a function of pH. Food Chem 2023; 408:135229. [PMID: 36563618 DOI: 10.1016/j.foodchem.2022.135229] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 11/28/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
The properties of milk proteins differ between mammalian species. β-Lactoglobulin (βlg) proteins from caprine and bovine milk are sequentially and structurally highly similar, yet their physicochemical properties differ, particularly in response to pH. To resolve this conundrum, we compared the dynamics of both the monomeric and dimeric states for each homologue at pH 6.9 and 7.5 using hydrogen/deuterium exchange experiments. At pH 7.5, the rate of exchange is similar across both homologues, but at pH 6.9 the dimeric states of the bovine βlg B variant homologue have significantly more conformational flexibility compared with caprine βlg. Molecular dynamics simulations provide a mechanistic rationale for the experimental observations, revealing that variant-specific substitutions encode different conformational ensembles with different dynamic properties consistent with the hydrogen/deuterium exchange experiments. Understanding the dynamic differences across βlg homologues is essential to understand the different responses of these milks to processing, human digestion, and differences in immunogenicity.
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Affiliation(s)
- Hannah J Mckerchar
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand; Riddet Institute, based at Massey University, Palmerston North 4442, New Zealand; Protein and Metabolites Team, AgResearch Lincoln Research Centre, Lincoln 7608, New Zealand
| | - Cristina Lento
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada
| | - Rachel Z Bennie
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand
| | - Jennifer M Crowther
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand
| | - Fabian Dolamore
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand
| | - Jolon M Dyer
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand; The New Zealand Institute for Plant and Food Research, Lincoln Research Centre, Lincoln 7608, New Zealand; Department of Wine, Food and Molecular Biosciences, Lincoln University, Lincoln 7647, New Zealand
| | - Stefan Clerens
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand; Riddet Institute, based at Massey University, Palmerston North 4442, New Zealand; Protein and Metabolites Team, AgResearch Lincoln Research Centre, Lincoln 7608, New Zealand
| | - Davide Mercadante
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
| | - Derek J Wilson
- Department of Chemistry, York University, Toronto, Ontario M3J 1P3, Canada; Centre for Research in Mass Spectrometry, Toronto, Ontario M3J 1P3, Canada
| | - Renwick C J Dobson
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand; Riddet Institute, based at Massey University, Palmerston North 4442, New Zealand; Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Victoria 3010, Australia.
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9
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Aya Rodriguez MD, Vidotto DC, Xavier AAO, Mantovani RA, Tavares GM. Does the protein structure of β-lactoglobulin impact its complex coacervation with type a gelatin and the ability of the complexes to entrap lutein? Food Hydrocoll 2023. [DOI: 10.1016/j.foodhyd.2023.108651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
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10
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Castillo O, Mancillas J, Hughes W, Brancaleon L. Characterization of the interaction of metal-protoporphyrins photosensitizers with β- lactoglobulin. Biophys Chem 2023; 292:106918. [PMID: 36399946 DOI: 10.1016/j.bpc.2022.106918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Revised: 10/24/2022] [Accepted: 10/27/2022] [Indexed: 11/17/2022]
Abstract
We investigated the interaction of a series of metal-protoporphyrins (PPIXs) with bovine β- lactoglobulin (BLG) using a combination of optical spectroscopy and computational simulations. Unlike other studies, the simulations were not merely used to rationalize the experimental data but were employed to refine the experimental data itself. The study was carried out at two pH values, 5 and 9, where BLG is known to have different conformation dictated by the so-called Tanford transition which occurs near pH 7.5. The transition is postulated to regulate access to the interior binding cavity of the protein, thus the pH variation was used as a parameter to investigate whether PPIXs access the central cavity of BLG. The results of our study show that indeed binding increases significantly at alkaline pH, however, the increased affinity is not due to the accessibility of the central cavity. Instead, binding appears to be determined by the tendency of PPIXs to form large inhomogeneous aggregates at acidic pH which hinders interactions with proteins. The binding site determined through a combination of experimental and computational methods is located at the interface between two BLG monomers where the long α-helix segment of the protein face each other. This region is rich in positively charged Lys residues that interact with the propionic acid chains of the protoporphyrins. Establishing the modality of binding between protoporphyrins and BLG would have important consequences for the use of BLG:PPIX complexes in applications such as artificial photoreceptors, artificial metallo-enzymes, delivery of photosensitizers for phototherapy and even solar energy conversion.
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Affiliation(s)
- Omar Castillo
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - James Mancillas
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - William Hughes
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, USA
| | - Lorenzo Brancaleon
- Department of Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX 78249, USA.
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11
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Nash S, Vachet RW. Gas-Phase Unfolding of Protein Complexes Distinguishes Conformational Isomers. J Am Chem Soc 2022; 144:22128-22139. [PMID: 36414315 DOI: 10.1021/jacs.2c09573] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Proteins can adopt different conformational states that are important for their biological function and, in some cases, can be responsible for their dysfunction. The essential roles that proteins play in biological systems make distinguishing the structural differences between these conformational states both fundamentally and practically important. Here, we demonstrate that collision-induced unfolding (CIU), in combination with ion mobility-mass spectrometry (IM-MS) measurements, distinguish subtly different conformational states for protein complexes. Using the open and closed states of the β-lactoglobulin (βLG) dimer as a model, we show that these two conformational isomers unfold during collisional activation to generate distinct states that are readily separated by IM-MS. Extensive molecular modeling of the CIU process reproduces the distinct unfolding intermediates and identifies the molecular details that explain why the two conformational states unfold in distinct ways. Strikingly, the open conformational state forms new electrostatic interactions upon collisional heating, while the closed state does not. These newly formed electrostatic interactions involve residues on the loop differentially positioned in the two βLG conformational isomers, highlighting that gas-phase unfolding pathways reflect aspects of solution structure. This combination of experiment and theory provides a path forward for distinguishing subtly different conformational isomers for protein complexes via gas-phase unfolding experiments. Our results also have implications for understanding how protein complexes dissociate in the gas phase, indicating that current models need to be refined to explain protein complex dissociation.
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Affiliation(s)
- Stacey Nash
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States
| | - Richard W Vachet
- Molecular and Cellular Biology Program, University of Massachusetts Amherst, Amherst, Massachusetts 01003, United States.,Department of Chemistry, University of Massachusetts Amherst, Amherst, Massachusetts 01003 United States
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12
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da Rocha L, Baptista AM, Campos SRR. Computational Study of the pH-Dependent Ionic Environment around β-Lactoglobulin. J Phys Chem B 2022; 126:9123-9136. [PMID: 36321840 PMCID: PMC9776516 DOI: 10.1021/acs.jpcb.2c03797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Ions are involved in multiple biological processes and may exist bound to biomolecules or may be associated with their surface. Although the presence of ions in nucleic acids has traditionally gained more interest, ion-protein interactions, often with a marked dependency on pH, are beginning to gather attention. Here we present a detailed analysis on the binding and distribution of ions around β-lactoglobulin using a constant-pH MD (CpHMD) method, at a pH range 3-8, and compare it with the more traditional Poisson-Boltzmann (PB) model and the existing experimental data. Most analyses used ion concentration maps built around the protein, obtained from either the CpHMD simulations or PB calculations. The requirements of approximate charge neutrality and ionic strength equal to bulk, imposed on the MD box, imply that the absolute value of the ion excess should be half the protein charge, which is in agreement with experimental observation on other proteins ( Proc. Natl. Acad. Sci. U.S.A. 2021, 118, e2015879118) and lends support to this protocol. In addition, the protein total charge (including territorially bound ions) estimated with MD is in excellent agreement with electrophoretic measurements. Overall, the CpHMD simulations show good agreement with the nonlinear form of the PB (NLPB) model but not with its linear form, which involves a theoretical inconsistency in the calculation of the concentration maps. In several analyses, the observed pH-dependent trends for the counterions and co-ions are those generally expected, and the ion concentration maps correctly converge to the bulk ionic strength as one moves away from the protein. Despite the overall similarity, the CpHMD and NLPB approaches show some discrepancies when analyzed in more detail, which may be related to an apparent overestimation of counterion excess and underestimation of co-ion exclusion by the NLPB model, particularly at short distances from the protein.
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13
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Christoffer C, Kihara D. Domain-Based Protein Docking with Extremely Large Conformational Changes. J Mol Biol 2022; 434:167820. [PMID: 36089054 PMCID: PMC9992458 DOI: 10.1016/j.jmb.2022.167820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Revised: 08/31/2022] [Accepted: 09/03/2022] [Indexed: 11/17/2022]
Abstract
Proteins are key components in many processes in living cells, and physical interactions with other proteins and nucleic acids often form key parts of their functions. In many cases, large flexibility of proteins as they interact is key to their function. To understand the mechanisms of these processes, it is necessary to consider the 3D structures of such protein complexes. When such structures are not yet experimentally determined, protein docking has long been present to computationally generate useful structure models. However, protein docking has long had the limitation that the consideration of flexibility is usually limited to very small movements or very small structures. Methods have been developed which handle minor flexibility via normal mode or other structure sampling, but new methods are required to model ordered proteins which undergo large-scale conformational changes to elucidate their function at the molecular level. Here, we present Flex-LZerD, a framework for docking such complexes. Via partial assembly multidomain docking and an iterative normal mode analysis admitting curvilinear motions, we demonstrate the ability to model the assembly of a variety of protein-protein and protein-nucleic acid complexes.
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Affiliation(s)
- Charles Christoffer
- Department of Computer Science, Purdue University, West Lafayette, IN 47907, USA
| | - Daisuke Kihara
- Department of Computer Science, Purdue University, West Lafayette, IN 47907, USA; Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA; Purdue University Center for Cancer Research, Purdue University, West Lafayette, IN 47907, USA.
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14
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Rodzik A, Railean V, Pomastowski P, Žuvela P, Wong MW, Buszewski B. The influence of zinc ions concentration on β-lactoglobulin structure – physicochemical properties of Zn–β-lactoglobulin complexes. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2022.133745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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15
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Chakraborty G. Red emitting fluorogenic dye as an efficient turn-on probe for milk allergen. Int J Biol Macromol 2022; 221:1527-1535. [PMID: 36122782 DOI: 10.1016/j.ijbiomac.2022.09.130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 09/14/2022] [Accepted: 09/14/2022] [Indexed: 11/24/2022]
Abstract
Development of simple, fast and non-destructive technique such as fluorescence based method for the quantification of milk allergens in various dairy products is a highly rewarding task. In this contribution, a red emitting fluorogenic dye, quinaldine red (QR) is reported for the detection and quantification of a milk allergen, beta lactoglobulin (β-LG) in milk and whey matrices, utilizing its high selectivity and sensitivity towards β-LG. Detail spectroscopic investigation reveals that binding of QR to the hydrophobic calyx site of β-LG protein substantially reduces the torsional agility and propensity of TICT state formation of QR, rendering the dye highly fluorescent in nature. This enables estimation of β-LG with LOD 52.1(±0.9) nM in buffer solution and 0.21(±0.01) μM in 5 % bovine milk matrix respectively. Additionally, high selectivity and sensitivity, excellent repeatability, quick response, and emission in the biologically favorable red spectral region make QR based fluorometric quantification of β-LG a highly attractive choice. Finally, the estimated β-LG concentrations in milk and whey matrices from fluorometric titration and densitometry methods are found to match excellently with each other, suggesting potential of QR as an efficient turn-on fluorescent probe for the quantification of β-LG (milk allergen) in various dairy products.
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Affiliation(s)
- Goutam Chakraborty
- Laser and Plasma Technology Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
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16
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Rodzik A, Railean V, Pomastowski P, Žuvela P, Wong MW, Sprynskyy M, Buszewski B. Study on silver ions binding to β-lactoglobulin. Biophys Chem 2022; 291:106897. [DOI: 10.1016/j.bpc.2022.106897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Revised: 09/13/2022] [Accepted: 09/22/2022] [Indexed: 11/02/2022]
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17
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Vinod SM, Sangeetha MS, Thamarai Selvan R, Shoba G, Tamizhdurai P, Kumaran R. Molecular docking approach on the molecular interactions involving beta-lactoglobulin (βLG)-4-Dicyanomethylene2,6-Dimethyl-4-Hpyran (DDP) dye in the presence of an antibiotic, norfloxacin. J INDIAN CHEM SOC 2022. [DOI: 10.1016/j.jics.2022.100477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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18
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Loch JI, Barciszewski J, Śliwiak J, Bonarek P, Wróbel P, Pokrywka K, Shabalin IG, Minor W, Jaskolski M, Lewiński K. New ligand-binding sites identified in the crystal structures of β-lactoglobulin complexes with desipramine. IUCRJ 2022; 9:386-398. [PMID: 35546795 PMCID: PMC9067113 DOI: 10.1107/s2052252522004183] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 04/19/2022] [Indexed: 06/15/2023]
Abstract
The homodimeric β-lactoglobulin belongs to the lipocalin family of proteins that transport a wide range of hydrophobic molecules and can be modified by mutagenesis to develop specificity for novel groups of ligands. In this work, new lactoglobulin variants, FAF (I56F/L39A/M107F) and FAW (I56F/L39A/M107W), were produced and their interactions with the tricyclic drug desipramine (DSM) were studied using X-ray crystallography, calorimetry (ITC) and circular dichroism (CD). The ITC and CD data showed micromolar affinity of the mutants for DSM and interactions according to the classical one-site binding model. However, the crystal structures unambiguously showed that the FAF and FAW dimers are capable of binding DSM not only inside the β-barrel as expected, but also at the dimer interface and at the entrance to the binding pocket. The presented high-resolution crystal structures therefore provide important evidence of the existence of alternative ligand-binding sites in the β-lactoglobulin molecule. Analysis of the crystal structures highlighted the importance of shape complementarity for ligand recognition and selectivity. The binding sites identified in the crystal structures of the FAF-DSM and FAW-DSM complexes together with data from the existing literature are used to establish a systematic classification of the ligand-binding sites in the β-lactoglobulin molecule.
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Affiliation(s)
- Joanna I. Loch
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Kraków, Poland
| | - Jakub Barciszewski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Joanna Śliwiak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Piotr Bonarek
- Department of Physical Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Kraków, Poland
| | - Paulina Wróbel
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Kraków, Poland
| | - Kinga Pokrywka
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Kraków, Poland
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Ivan G. Shabalin
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
| | - Wladek Minor
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia, USA
| | - Mariusz Jaskolski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
- Department of Crystallography, Faculty of Chemistry, A. Mickiewicz University, Poznan, Poland
| | - Krzysztof Lewiński
- Department of Crystal Chemistry and Crystal Physics, Faculty of Chemistry, Jagiellonian University, Kraków, Poland
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19
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Xia N, Wang C, Zhu S. Interaction between pH-shifted ovalbumin and insoluble neohesperidin: Experimental and binding mechanism studies. Food Chem 2022; 390:133104. [PMID: 35561507 DOI: 10.1016/j.foodchem.2022.133104] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Revised: 04/25/2022] [Accepted: 04/26/2022] [Indexed: 11/30/2022]
Abstract
In this study, ovalbumin (OVA) formed a complex with neohesperidin (NH) via a pH-shifting method. The NH-OVA complex self-assembled into NH-OVA nano-particles, which were then characterized and whose binding mechanism was evaluated by using multi-spectroscopic, thermodynamics, and molecular docking simulation methods. Fluorescence intensity decreased after OVA was complexed with NH. The binding constant of the OVA-NH complex was in the order of 6.32 × 105 M-1 suggesting that the complex is stable. Circular dichroism (CD) analysis showed that α -helix content increased, β-folding, β -turning, and irregular crimp content decreased after OVA and NH binding. Isothermal titration calorimetry results showed that hydrophobic interactions and hydrogen bonds made an important impact in the complex formation. The molecular docking results revealed that Van der Waals forces and hydrogen bonds contributed to the free binding energy of the complex. There were multiple possible surface binding sites between OVA with NH. The obtained results provide new insights into the interaction mechanism of OVA and NH, and as a vehicle for NH, the OVA has shown promising applications in functional foods.
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Affiliation(s)
- Na Xia
- School of Food Science & Engineering, South China University of Technology, Guangzhou 510641, PR China; College of Life and Geographic Sciences, Kashi University, Kashi 844000, PR China; Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center), Guangzhou 510640, PR China
| | - Chunqing Wang
- School of Food Science & Engineering, South China University of Technology, Guangzhou 510641, PR China
| | - Siming Zhu
- School of Food Science & Engineering, South China University of Technology, Guangzhou 510641, PR China; Overseas Expertise Introduction Center for Discipline Innovation of Food Nutrition and Human Health (111 Center), Guangzhou 510640, PR China.
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20
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Insights from alpha-Lactoalbumin and beta-Lactoglobulin into mechanisms of nanoliposome-whey protein interactions. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2021.107436] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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21
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Andlinger DJ, Schlemmer L, Jung I, Schroeter B, Smirnova I, Kulozik U. Hydro- and aerogels from ethanolic potato and whey protein solutions: Influence of temperature and ethanol concentration on viscoelastic properties, protein interactions, and microstructure. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2021.107424] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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22
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da Rocha L, Baptista AM, Campos SRR. Approach to Study pH-Dependent Protein Association Using Constant-pH Molecular Dynamics: Application to the Dimerization of β-Lactoglobulin. J Chem Theory Comput 2022; 18:1982-2001. [PMID: 35171602 PMCID: PMC9775224 DOI: 10.1021/acs.jctc.1c01187] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Protein-protein association is often mediated by electrostatic interactions and modulated by pH. However, experimental and computational studies have often overlooked the effect of association on the protonation state of the protein. In this work, we present a methodological approach based on constant-pH molecular dynamics (MD), which aims to provide a detailed description of a pH-dependent protein-protein association, and apply it to the dimerization of β-lactoglobulin (BLG). A selection of analyses is performed using the data generated by constant-pH MD simulations of monomeric and dimeric forms of bovine BLG, in the pH range 3-8. First, we estimate free energies of dimerization using a computationally inexpensive approach based on the Wyman-Tanford linkage theory, calculated in a new way through the use of thermodynamically based splines. The individual free energy contribution of each titratable site is also calculated, allowing for identification of relevant residues. Second, the correlations between the proton occupancies of pairs of sites are calculated (using the Pearson coefficient), and extensive networks of correlated sites are observed at acidic pH values, sometimes involving distant pairs. In general, strongly correlated sites are also slow proton exchangers and contribute significantly to the pH-dependency of the dimerization free energy. Third, we use ionic density as a fingerprint of protein charge distribution and observe electrostatic complementarity between the monomer faces that form the dimer interface, more markedly at the isoionic point (where maximum dimerization occurs) than at other pH values, which might contribute to guide the association. Finally, the pH-dependent dimerization modes are inspected using PCA, among other analyses, and two states are identified: a relaxed state at pH 4-8 (with the typical alignment of the crystallographic structure) and a compact state at pH 3-4 (with a tighter association and rotated alignment). This work shows that an approach based on constant-pH MD simulations can produce rich detailed pictures of pH-dependent protein associations, as illustrated for BLG dimerization.
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23
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Structural and rheological behavior of β-lactoglobulins influenced by high hydrostatic pressure – From a single molecule to the aggregates. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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24
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Radomirovic M, Minic S, Stanic-Vucinic D, Nikolic M, Van Haute S, Rajkovic A, Cirkovic Velickovic T. Phycocyanobilin-modified β-lactoglobulin exhibits increased antioxidant properties and stability to digestion and heating. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2021.107169] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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25
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Fenner K, Redgate A, Brancaleon L. A 200 nanoseconds all-atom simulation of the pH-dependent EF loop transition in bovine β-lactoglobulin. The role of the orientation of the E89 side chain. J Biomol Struct Dyn 2022; 40:549-564. [PMID: 32909899 PMCID: PMC8853732 DOI: 10.1080/07391102.2020.1817785] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In silico molecular dynamics (MD) using crystallographic and NMR data was used to simulate the effects of the protonation state of E89 on the pH-dependent conformational rearrangement of the EF loop, also known as the Tanford transition, in a series of apo-β-lactoglobulin (BLG) structures. Compared to existing studies these simulations were carried out over a much longer time scale (200 ns where the stability of the transition can be evaluated) and used an explicit water model. We considered eight different entries from the Brookhaven Protein Data Bank (PDB) separated into two groups. We observed that fixing the protonation state of E89 prompts the transition of the EF loop only when its side chain is oriented under the loop and into the entrance of the interior cavity. The motion of the EF loop occurs mostly as a step-function and its timing varies greatly from ∼ 20 ns to ∼170 ns from the beginning of the simulation. Once the transition is completed, the protein appears to reach a stable conformation as in a true two-state transition. We also observed novel findings. When the transition occurs, the hydrogen bond between E89 and S116 is replaced with a salt bridge with Lys residues in the βC-CD loop-βD motif. This electrostatic interaction causes the distortion of this motif as well as the protrusion of the GH loop into the aperture of the cavity with the result of limiting the increase of its contour area despite the rotation of the EF loop.Communicated by Ramaswamy H. Sarma.
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26
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Simulation of pH-Dependent Conformational Transitions in Membrane Proteins: The CLC-ec1 Cl -/H + Antiporter. Molecules 2021; 26:molecules26226956. [PMID: 34834047 PMCID: PMC8625536 DOI: 10.3390/molecules26226956] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Revised: 11/09/2021] [Accepted: 11/16/2021] [Indexed: 11/17/2022] Open
Abstract
Intracellular transport of chloride by members of the CLC transporter family involves a coupled exchange between a Cl− anion and a proton (H+), which makes the transport function dependent on ambient pH. Transport activity peaks at pH 4.5 and stalls at neutral pH. However, a structure of the WT protein at acidic pH is not available, making it difficult to assess the global conformational rearrangements that support a pH-dependent gating mechanism. To enable modeling of the CLC-ec1 dimer at acidic pH, we have applied molecular dynamics simulations (MD) featuring a new force field modification scheme—termed an Equilibrium constant pH approach (ECpH). The ECpH method utilizes linear interpolation between the force field parameters of protonated and deprotonated states of titratable residues to achieve a representation of pH-dependence in a narrow range of physiological pH values. Simulations of the CLC-ec1 dimer at neutral and acidic pH comparing ECpH-MD to canonical MD, in which the pH-dependent protonation is represented by a binary scheme, substantiates the better agreement of the conformational changes and the final model with experimental data from NMR, cross-link and AFM studies, and reveals structural elements that support the gate-opening at pH 4.5, including the key glutamates Gluin and Gluex.
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27
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Nguyen TT, Marzolf DR, Seffernick JT, Heinze S, Lindert S. Protein structure prediction using residue-resolved protection factors from hydrogen-deuterium exchange NMR. Structure 2021; 30:313-320.e3. [PMID: 34739840 DOI: 10.1016/j.str.2021.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 08/04/2021] [Accepted: 10/15/2021] [Indexed: 11/17/2022]
Abstract
Hydrogen-deuterium exchange (HDX) measured by nuclear magnetic resonance (NMR) provides structural information for proteins relating to solvent accessibility and flexibility. While this structural information is beneficial, the data cannot be used exclusively to elucidate structures. However, the structural information provided by the HDX-NMR data can be supplemented by computational methods. In previous work, we developed an algorithm in Rosetta to predict structures using qualitative HDX-NMR data (categories of exchange rate). Here we expand on the effort, and utilize quantitative protection factors (PFs) from HDX-NMR for structure prediction. From observed correlations between PFs and solvent accessibility/flexibility measures, we present a scoring function to quantify the agreement with HDX data. Using a benchmark set of 10 proteins, an average improvement of 5.13 Å in root-mean-square deviation (RMSD) is observed for cases of inaccurate Rosetta predictions. Ultimately, seven out of 10 predictions are accurate without including HDX data, and nine out of 10 are accurate when using our PF-based HDX score.
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Affiliation(s)
- Tung T Nguyen
- Department of Chemistry and Biochemistry, Denison University, Granville, OH 43023, USA
| | - Daniel R Marzolf
- Department of Chemistry and Biochemistry, Ohio State University, 2114 Newman & Wolfrom Laboratory, 100 W. 18(th) Avenue, Columbus, OH 43210, USA
| | - Justin T Seffernick
- Department of Chemistry and Biochemistry, Ohio State University, 2114 Newman & Wolfrom Laboratory, 100 W. 18(th) Avenue, Columbus, OH 43210, USA
| | - Sten Heinze
- Department of Chemistry and Biochemistry, Ohio State University, 2114 Newman & Wolfrom Laboratory, 100 W. 18(th) Avenue, Columbus, OH 43210, USA
| | - Steffen Lindert
- Department of Chemistry and Biochemistry, Ohio State University, 2114 Newman & Wolfrom Laboratory, 100 W. 18(th) Avenue, Columbus, OH 43210, USA.
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28
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Gai N, Uniacke-Lowe T, O’Regan J, Faulkner H, Kelly AL. Effect of Protein Genotypes on Physicochemical Properties and Protein Functionality of Bovine Milk: A Review. Foods 2021; 10:2409. [PMID: 34681458 PMCID: PMC8535582 DOI: 10.3390/foods10102409] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/29/2021] [Accepted: 09/30/2021] [Indexed: 12/05/2022] Open
Abstract
Milk protein comprises caseins (CNs) and whey proteins, each of which has different genetic variants. Several studies have reported the frequencies of these genetic variants and the effects of variants on milk physicochemical properties and functionality. For example, the C variant and the BC haplotype of αS1-casein (αS1-CN), β-casein (β-CN) B and A1 variants, and κ-casein (κ-CN) B variant, are favourable for rennet coagulation, as well as the B variant of β-lactoglobulin (β-lg). κ-CN is reported to be the only protein influencing acid gel formation, with the AA variant contributing to a firmer acid curd. For heat stability, κ-CN B variant improves the heat resistance of milk at natural pH, and the order of heat stability between phenotypes is BB > AB > AA. The A2 variant of β-CN is more efficient in emulsion formation, but the emulsion stability is lower than the A1 and B variants. Foaming properties of milk with β-lg variant B are better than A, but the differences between β-CN A1 and A2 variants are controversial. Genetic variants of milk proteins also influence milk yield, composition, quality and processability; thus, study of such relationships offers guidance for the selection of targeted genetic variants.
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Affiliation(s)
- Nan Gai
- School of Food and Nutritional Sciences, University College Cork, T12 YN60 Cork, Ireland; (N.G.); (T.U.-L.)
| | - Therese Uniacke-Lowe
- School of Food and Nutritional Sciences, University College Cork, T12 YN60 Cork, Ireland; (N.G.); (T.U.-L.)
| | - Jonathan O’Regan
- Nestlé Development Centre Nutrition, Wyeth Nutritionals Ireland, Askeaton, Co., V94 E7P9 Limerick, Ireland; (J.O.); (H.F.)
| | - Hope Faulkner
- Nestlé Development Centre Nutrition, Wyeth Nutritionals Ireland, Askeaton, Co., V94 E7P9 Limerick, Ireland; (J.O.); (H.F.)
| | - Alan L. Kelly
- School of Food and Nutritional Sciences, University College Cork, T12 YN60 Cork, Ireland; (N.G.); (T.U.-L.)
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29
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Hinderink EB, Berton-Carabin CC, Schroën K, Riaublanc A, Houinsou-Houssou B, Boire A, Genot C. Conformational Changes of Whey and Pea Proteins upon Emulsification Approached by Front-Surface Fluorescence. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2021; 69:6601-6612. [PMID: 34087067 PMCID: PMC8213056 DOI: 10.1021/acs.jafc.1c01005] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 04/11/2021] [Accepted: 05/17/2021] [Indexed: 06/12/2023]
Abstract
Proteins are widely used to stabilize emulsions, and plant proteins have raised increasing interest for this purpose. The interfacial and emulsifying properties of proteins depend largely on their molecular properties. We used fluorescence spectroscopy to characterize the conformation of food proteins from different biological origins (dairy or pea) and transformation processes (commercial or lab-made isolates) in solution and at the oil-water interface. The fourth derivative of fluorescence spectra provided insights in the local environment of tryptophan (Trp) residues and thus in the protein structure. In emulsions, whey proteins adsorbed with their Trp-rich region at the oil-water interface. Proteins in the commercial pea isolate were present as soluble aggregates, and no changes in the local environment of the Trp residues were detected upon emulsification, suggesting that these structures adsorb without conformational changes. The lab-purified pea proteins were less aggregated and a Trp-free region of the vicilin adsorbed at the oil-water interface.
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Affiliation(s)
- Emma B.
A. Hinderink
- TiFN, P.O. Box 557, 6700 AN Wageningen, The Netherlands
- Laboratory
of Food Process Engineering, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
| | - Claire C. Berton-Carabin
- Laboratory
of Food Process Engineering, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
- INRAE,
UR BIA, F-44316 Nantes, France
| | - Karin Schroën
- Laboratory
of Food Process Engineering, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands
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30
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Wang C, Chen L, Lu Y, Liu J, Zhao R, Sun Y, Sun B, Cuina W. pH-Dependent complexation between β-lactoglobulin and lycopene: Multi-spectroscopy, molecular docking and dynamic simulation study. Food Chem 2021; 362:130230. [PMID: 34098435 DOI: 10.1016/j.foodchem.2021.130230] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2021] [Revised: 05/16/2021] [Accepted: 05/26/2021] [Indexed: 12/24/2022]
Abstract
This study aims to investigate the effect of pH levels (pH 7.0 and pH 8.1) on binding ability of β-lactoglobulin (β-LG) with lycopene (LYC) and elucidate interaction mechanisms using multi-spectroscopy and molecular docking study. β-LG at pH 8.1 showed a stronger binding affinity to lycopene than that at pH 7.0 according to binding constant, binding number, energy transfer efficiency, and surface hydrophobicity. Lycopene bound to protein mainly by van der Waals force in the form of static quenching mode and preferred to interact with β-LG at the top of barrel for both pH levels. Molecular dynamic simulation revealed that β-LG/LYC complex at pH 8.1 was more stable than at pH 7.0. β-LG/LYC complexes formed at pH 8.1 showed significantly higher ABTS radical scavenging activity than samples at pH 7.0 (p < 0.05). Data obtained may contribute valuable information for preparing a whey protein-based delivery system for lycopene.
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Affiliation(s)
- Ce Wang
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Lu Chen
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Yingcong Lu
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Jia Liu
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Ru Zhao
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Yonghai Sun
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Boyang Sun
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Wang Cuina
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun 130062, China.
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31
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Sawyer L. β-Lactoglobulin and Glycodelin: Two Sides of the Same Coin? Front Physiol 2021; 12:678080. [PMID: 34093238 PMCID: PMC8173191 DOI: 10.3389/fphys.2021.678080] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 04/14/2021] [Indexed: 12/22/2022] Open
Abstract
The two lipocalins, β-lactoglobulin (βLg) and glycodelin (Gd), are possibly the most closely related members of the large and widely distributed lipocalin family, yet their functions appear to be substantially different. Indeed, the function of β-lactoglobulin, a major component of ruminant milk, is still unclear although neonatal nutrition is clearly important. On the other hand, glycodelin has several specific functions in reproduction conferred through distinct, tissue specific glycosylation of the polypeptide backbone. It is also associated with some cancer outcomes. The glycodelin gene, PAEP, reflecting one of its names, progestagen-associated endometrial protein, is expressed in many though not all primates, but the name has now also been adopted for the β-lactoglobulin gene (HGNC, www.genenames.org). After a general overview of the two proteins in the context of the lipocalin family, this review considers the properties of each in the light of their physiological functional significance, supplementing earlier reviews to include studies from the past decade. While the biological function of glycodelin is reasonably well defined, that of β-lactoglobulin remains elusive.
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Affiliation(s)
- Lindsay Sawyer
- School of Biological Sciences, IQB3, The University of Edinburgh, Edinburgh, United Kingdom
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32
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Lan W, Valente JJ, Ilott A, Chennamsetty N, Liu Z, Rizzo JM, Yamniuk AP, Qiu D, Shackman HM, Bolgar MS. Investigation of anomalous charge variant profile reveals discrete pH-dependent conformations and conformation-dependent charge states within the CDR3 loop of a therapeutic mAb. MAbs 2021; 12:1763138. [PMID: 32432964 PMCID: PMC7299213 DOI: 10.1080/19420862.2020.1763138] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
During the development of a therapeutic monoclonal antibody (mAb-1), the charge variant profile obtained by pH-gradient cation exchange chromatography (CEX) contained two main peaks, each of which exhibited a unique intrinsic fluorescence profile and demonstrated inter-convertibility upon reinjection of isolated peak fractions. Domain analysis of mAb-1 by CEX and liquid chromatography-mass spectrometry indicated that the antigen-binding fragment chromatographed as two separate peaks that had identical mass. Surface plasmon resonance binding analysis to antigen demonstrated comparable kinetics/affinity between these fractionated peaks and unfractionated starting material. Subsequent molecular modeling studies revealed that the relatively long and flexible complementarity-determining region 3 (CDR3) loop on the heavy chain could adopt two discrete pH-dependent conformations: an “open” conformation at neutral pH where the HC-CDR3 is largely solvent exposed, and a “closed” conformation at lower pH where the solvent exposure of a neighboring tryptophan in the light chain is reduced and two aspartic acid residues near the ends of the HC-CDR3 loop have atypical pKa values. The pH-dependent equilibrium between “open” and “closed” conformations of the HC-CDR3, and its proposed role in the anomalous charge variant profile of mAb-1, were supported by further CEX and hydrophobic interaction chromatography studies. This work is an example of how pH-dependent conformational changes and conformation-dependent changes to net charge can unexpectedly contribute to perceived instability and require thorough analytical, biophysical, and functional characterization during biopharmaceutical drug product development.
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Affiliation(s)
- Wenkui Lan
- Drug Product Development, Bristol Myers Squibb, New Brunswick, United States
| | - Joseph J Valente
- Drug Product Development, Bristol Myers Squibb, New Brunswick, United States
| | - Andrew Ilott
- Drug Product Development, Bristol Myers Squibb, New Brunswick, United States
| | - Naresh Chennamsetty
- Biophysics Center of Excellence, Global Product Development and Supply, Bristol Myers Squibb, New Brunswick, United States
| | - Zhihua Liu
- Drug Product Development, Bristol Myers Squibb, New Brunswick, United States
| | - Joseph M Rizzo
- Discovery Biotherapeutics, Bristol Myers Squibb, Pennington, United States
| | - Aaron P Yamniuk
- Discovery Biotherapeutics, Bristol Myers Squibb, Pennington, United States
| | - Difei Qiu
- Chemical Process Department, Bristol Myers Squibb, New Brunswick, United States
| | - Holly M Shackman
- Chemical Process Department, Bristol Myers Squibb, New Brunswick, United States
| | - Mark S Bolgar
- Drug Product Development, Bristol Myers Squibb, New Brunswick, United States
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33
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Fei S, Zhou J, Wu Y, Tong P, Gao J, Chen H, Li X. Change in conformational, digestive and immunological characteristics of bovine allergen β-lactoglobulin induced by metal ions in combination with heating. Food Chem 2021; 364:130030. [PMID: 34198035 DOI: 10.1016/j.foodchem.2021.130030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 10/21/2022]
Abstract
Aggregation of bovine β-lactoglobulin is affected easily by external factors. In this study, effects of metal ions combining with temperature on aggregation of β-lactoglobulin were explored. The conformational characteristics of aggregates were detected by environment scanning electron microscope, CD spectrum and free sulfhydryl group, respectively. Digestive and immunological characteristics were assessed by simulated digestion in vitro and ELISA respectively. The results showed that the morphology of β-lactoglobulin aggregates became more amorphous in Cu2+ and Mg2+ treated samples and more constricted in Zu2+-induced protein. Among them, Cu2+ altered the secondary structure of β-lactoglobulin aggregates and free sulfhydryl content most as well as that in gastric digestion. However, all ion-treated groups had similar digestive stability in intestinal digestion. Specially, Ca2+ and Mg2+ made the antigenicity and potential allergenicity of β-lactoglobulin aggregates decrease, which helps us understand the role of metal ions in immunological characteristics.
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Affiliation(s)
- Shuangwen Fei
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, PR China; School of Food Science and Technology, Nanchang University, Nanchang 330047, PR China
| | - Jianwen Zhou
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, PR China; School of Food Science and Technology, Nanchang University, Nanchang 330047, PR China
| | - Yong Wu
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, PR China; School of Food Science and Technology, Nanchang University, Nanchang 330047, PR China
| | - Ping Tong
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, PR China
| | - Jingyan Gao
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, PR China; School of Food Science and Technology, Nanchang University, Nanchang 330047, PR China
| | - Hongbing Chen
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, PR China; Sino-German Joint Research Institute, Nanchang University, Nanchang 330047, PR China
| | - Xin Li
- State Key Laboratory of Food Science and Technology, Nanchang University, Nanchang 330047, PR China; School of Food Science and Technology, Nanchang University, Nanchang 330047, PR China.
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34
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Kieserling H, Pankow A, Keppler JK, Wagemans AM, Drusch S. Conformational state and charge determine the interfacial film formation and film stability of β-lactoglobulin. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2020.106561] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
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35
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Birch J, Khan S, Madsen M, Kjeldsen C, Møller MS, Stender EGP, Peters GJ, Duus JØ, Kragelund BB, Svensson B. Binding Sites for Oligosaccharide Repeats from Lactic Acid Bacteria Exopolysaccharides on Bovine β-Lactoglobulin Identified by NMR Spectroscopy. ACS OMEGA 2021; 6:9039-9052. [PMID: 33842774 PMCID: PMC8028130 DOI: 10.1021/acsomega.1c00060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 03/11/2021] [Indexed: 05/26/2023]
Abstract
Lactic acid bacterial exopolysaccharides (EPS) are used in the food industry to improve the stability and rheological properties of fermented dairy products. β-Lactoglobulin (BLG), the dominant whey protein in bovine milk, is well known to bind small molecules such as fatty acids, vitamins, and flavors, and to interact with neutral and anionic polysaccharides used in food and pharmaceuticals. While sparse data are available on the affinity of EPS-milk protein interactions, structural information on BLG-EPS complexes, including the EPS binding sites, is completely lacking. Here, binding sites on BLG variant A (BLGA), for oligosaccharides prepared by mild acid hydrolysis of two EPS produced by Streptococcus thermophilus LY03 and Lactobacillus delbrueckii ssp. bulgaricus CNRZ 1187, respectively, are identified by NMR spectroscopy and supplemented by isothermal titration calorimetry (ITC) and molecular docking of complexes. Evidence of two binding sites (site 1 and site 2) on the surface of BLGA is achieved for both oligosaccharides (LY03-OS and 1187-OS) through NMR chemical shift perturbations, revealing multivalency of BLGA for EPS. The affinities of LY03-OS and 1187-OS for BLGA gave K D values in the mM range obtained by both NMR (pH 2.65) and ITC (pH 4.0). Molecular docking suggested that the BLGA and EPS complexes depend on hydrogen bonds and hydrophobic interactions. The findings provide insights into how BLGA engages structurally different EPS-derived oligosaccharides, which may facilitate the design of BLG-EPS complexation, of relevance for formulation of dairy products and improve understanding of BLGA coacervation.
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Affiliation(s)
- Johnny Birch
- Enzyme
and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
| | - Sanaullah Khan
- Enzyme
and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
| | - Mikkel Madsen
- Enzyme
and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
| | - Christian Kjeldsen
- NMR
Spectroscopy, Department of Chemistry, Technical
University of Denmark, Kemitorvet 207, DK-2800 Kgs. Lyngby, Denmark
| | - Marie Sofie Møller
- Enzyme
and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
| | - Emil G. P. Stender
- Enzyme
and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
| | - Günther
H. J. Peters
- Biophysical
and Biomedicinal Chemistry, Department of Chemistry, Technical University of Denmark, Kemitorvet 206, DK-2800
Kgs. Lyngby, Denmark
| | - Jens Ø. Duus
- NMR
Spectroscopy, Department of Chemistry, Technical
University of Denmark, Kemitorvet 207, DK-2800 Kgs. Lyngby, Denmark
| | - Birthe B. Kragelund
- Structural
Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaloes Vej 5, DK-2200 Copenhagen N, Denmark
| | - Birte Svensson
- Enzyme
and Protein Chemistry, Department of Biotechnology and Biomedicine, Technical University of Denmark, Søltofts Plads, Building 224, DK-2800 Kgs. Lyngby, Denmark
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36
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Energetic and structural effects of the Tanford transition on ligand recognition of bovine β-lactoglobulin. Arch Biochem Biophys 2021; 699:108750. [PMID: 33421379 DOI: 10.1016/j.abb.2020.108750] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/28/2020] [Accepted: 12/30/2020] [Indexed: 01/14/2023]
Abstract
Bovine β-lactoglobulin, an abundant protein in whey, is a promising nanocarrier for peroral administration of drug-like hydrophobic molecules, a process that involves transit through the different acidic conditions of the human digestive tract. Among the several pH-induced conformational rearrangements that this lipocalin undergoes, the Tanford transition is particularly relevant. This transition, which occurs with a midpoint around neutral pH, involves a conformational change of the E-F loop that regulates accessibility to the primary binding site. The effect of this transition on the ligand binding properties of this protein has scarcely been explored. In this study, we carried out an energetic and structural characterization of β-lactoglobulin molecular recognition at pH values above and below the zone in which the Tanford transition occurs. The combined analysis of crystallographic, calorimetric, and molecular dynamics data sheds new light on the interplay between self-association, ligand binding, and the Tanford pre- and post-transition conformational states, revealing novel aspects underlying the molecular recognition mechanism of this enigmatic lipocalin.
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37
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Small angle X-ray scattering analysis of ligand-bound forms of tetrameric apolipoprotein-D. Biosci Rep 2021; 41:227100. [PMID: 33399852 PMCID: PMC7786332 DOI: 10.1042/bsr20201423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 12/01/2020] [Accepted: 12/01/2020] [Indexed: 11/17/2022] Open
Abstract
Human apolipoprotein-D (apoD) is a glycosylated lipocalin that plays a protective role in Alzheimer's disease due to its antioxidant function. Native apoD from human body fluids forms oligomers, predominantly a stable tetramer. As a lipocalin, apoD binds and transports small hydrophobic molecules such as progesterone, palmitic acid and sphingomyelin. Oligomerisation is a common trait in the lipocalin family and is affected by ligand binding in other lipocalins. The crystal structure of monomeric apoD shows no major changes upon progesterone binding. Here, we used small-angle X-ray scattering (SAXS) to investigate the influence of ligand binding and oxidation on apoD oligomerisation and conformation. As a solution-based technique, SAXS is well suited to detect changes in oligomeric state and conformation in response to ligand binding. Our results show no change in oligomeric state of apoD and no major conformational changes or subunit rearrangements in response to binding of ligands or protein oxidation. This highlights the highly stable structure of the native apoD tetramer under various physiologically relevant experimental conditions.
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38
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Chen X, Liu J, Jiang L, Zhang Y, Ren F, Zhang H. Characterization, spectroscopic and crystallographic analyses of β-lactoglobulin and docosahexaenoic acid nanocomplexes. Food Chem 2020; 330:127145. [PMID: 32531640 DOI: 10.1016/j.foodchem.2020.127145] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 04/29/2020] [Accepted: 05/23/2020] [Indexed: 10/24/2022]
Abstract
In this work, we investigated the interaction of docosahexaenoic acid (DHA) with β-lactoglobulin (β-Lg) using spectroscopic and crystallographic methods. The fluorescence results showed that DHA formed complexes with β-Lg with a binding constant of 4.13 × 104 M-1. The secondary structure of β-Lg was not significantly (p > 0.05) changed after binding with DHA. Dynamic light scattering showed the particle size of β-Lg-DHA complexes was about 5 nm, the same as that of β-Lg alone. The turbidity of DHA in aqueous solution decreased after binding with β-Lg. The crystallographic results showed that DHA was bound at one site in the calyx of β-Lg and that the aliphatic chain was hidden inside the hydrophobic β-barrel while the carboxyl group was located at the calyx entrance. These findings indicate that β-Lg can act as an effective nanocarrier for DHA.
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Affiliation(s)
- Xiulin Chen
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
| | - Jingwen Liu
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
| | - Lun Jiang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
| | - Yunyue Zhang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Xinghua Industrial Research Centre for Food Science and Human Health, China Agricultural University, Xinghua 225700, Jiangsu, China.
| | - Fazheng Ren
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China.
| | - Hao Zhang
- Beijing Advanced Innovation Center for Food Nutrition and Human Health, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China; Xinghua Industrial Research Centre for Food Science and Human Health, China Agricultural University, Xinghua 225700, Jiangsu, China.
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39
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Milea ȘA, Aprodu I, Mihalcea L, Enachi E, Bolea CA, Râpeanu G, Bahrim GE, Stănciuc N. Bovine β-lactoglobulin peptides as novel carriers for flavonoids extracted with supercritical fluids from yellow onion skins. J Food Sci 2020; 85:4290-4299. [PMID: 33175407 DOI: 10.1111/1750-3841.15513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/05/2020] [Accepted: 10/11/2020] [Indexed: 11/29/2022]
Abstract
Our study describes in detail the binding mechanism between the main flavonoids that were extracted from onion skins by supercritical CO2 and peptides from whey proteins, from the perspective of obtaining multifunctional ingredients, with health-promoting benefits. The supercritical CO2 extract had 202.31 ± 11.56 mg quercetin equivalents/g DW as the major flavonoid and antioxidant activity of 404.93±1.39 mM Trolox/g DW. The experiments on thermolysin-derived peptides fluorescence quenching by flavonoids extract allowed estimating the binding parameters, in terms of binding constants, and the number of binding sites. The thermodynamic analysis indicated that the main forces involved in complex formation were hydrogen bonds and van der Waals interactions. Molecular docking tests indicated that peptide fluorescence quenching upon gradual addition of onion skin extract might be due to flavonoids binding by Val15 -Ser21 . All 7 to 14 amino acids long peptides appeared to have affinity toward quercetin-3,4'-O-diglucoside and quercetin-4'-O-monoglucoside. The study is important as a potential solution for reuse of valuable resources, underutilized, such as whey peptides and yellow onion skins flavonoids for efficient microencapsulation, as a holistic approach to deliver healthy and nutritious food. PRACTICAL APPLICATION: A growing interest was noticed in the last years in investigating the interactions between proteins and different biologically active compounds, such as to provide knowledge for efficient development of new food, pharmaceutical, and cosmetic products. Recent studies suggest that flavonoid-protein complexes may be designed to improve the functional performance of the flavonoids. The results obtained in this study bring certain benefits in terms of exploiting the bioactive potential of both flavonoids and bioactive peptides, for developing of formulas with improved functional properties.
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Affiliation(s)
- Ștefania Adelina Milea
- Faculty of Food Science and Engineering, Dunărea de Jos University of Galati, 111 Domnească Street, Galati, 800201, Romania
| | - Iuliana Aprodu
- Faculty of Food Science and Engineering, Dunărea de Jos University of Galati, 111 Domnească Street, Galati, 800201, Romania
| | - Liliana Mihalcea
- Faculty of Food Science and Engineering, Dunărea de Jos University of Galati, 111 Domnească Street, Galati, 800201, Romania
| | - Elena Enachi
- Faculty of Food Science and Engineering, Dunărea de Jos University of Galati, 111 Domnească Street, Galati, 800201, Romania
| | - Carmen Alina Bolea
- Faculty of Food Science and Engineering, Dunărea de Jos University of Galati, 111 Domnească Street, Galati, 800201, Romania
| | - Gabriela Râpeanu
- Faculty of Food Science and Engineering, Dunărea de Jos University of Galati, 111 Domnească Street, Galati, 800201, Romania
| | - Gabriela Elena Bahrim
- Faculty of Food Science and Engineering, Dunărea de Jos University of Galati, 111 Domnească Street, Galati, 800201, Romania
| | - Nicoleta Stănciuc
- Faculty of Food Science and Engineering, Dunărea de Jos University of Galati, 111 Domnească Street, Galati, 800201, Romania
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40
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Bello M. Structural mechanism of the Tanford transition of bovine β-lactoglobulin through microsecond molecular dynamics simulations. J Biomol Struct Dyn 2020; 40:3011-3023. [PMID: 33155532 DOI: 10.1080/07391102.2020.1844062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
X-ray analysis has provided structural data about a pH-driven conformational change in β-lactoglobulin (BLG) known as the Tanford transition, which occurs at around pH 7 and involves the EF loop, which acts as a lid closing the internal cavity of the protein below pH 7 and opening it above pH 7. NMR studies using wild-type BLG have encountered problems trying to explain the Tanford transition, however, they have provided important insight using a dimeric BLG mutant, revealing that the opening and closure of the EF loop consists of two types of motions in the microsecond and milliseconds timescales. This provides valuable information indicating that the dimeric state is a good model to study the Tanford transition, although the understanding of this structural change is still lacking at the atomic level. We performed microsecond molecular dynamics (MD) simulations starting from different conformations of BLG in the monomeric and dimeric state, with protonated and deprotonated E89, in order to explore the Tanford transition. Our results provide structural information for the transition from the closed to the open conformation in BLG and show it occurs in the dimeric state in the microsecond timescale, in line with the fast motion observed through NMR experiments. In addition, MD simulations coupled to MMGBSA approach indicated that the most populated conformer of BLG in the open state is able to bind ligands with similar affinity to that of BLG at neutral pH obtained through crystallographic experiments.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Martiniano Bello
- Laboratorio de Modelado Molecular, Bioinformática y Diseño de Fármacos de la Escuela Superior de Medicina, Instituto Politécnico Nacional, Mexico City, Mexico
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41
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Crowther JM, Broadhurst M, Laue TM, Jameson GB, Hodgkinson AJ, Dobson RCJ. On the utility of fluorescence-detection analytical ultracentrifugation in probing biomolecular interactions in complex solutions: a case study in milk. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2020; 49:677-685. [PMID: 33052462 DOI: 10.1007/s00249-020-01468-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 09/25/2020] [Accepted: 09/29/2020] [Indexed: 12/24/2022]
Abstract
β-Lactoglobulin is the most abundant protein in the whey fraction of ruminant milks, yet is absent in human milk. It has been studied intensively due to its impact on the processing and allergenic properties of ruminant milk products. However, the physiological function of β-lactoglobulin remains unclear. Using the fluorescence-detection system within the analytical ultracentrifuge, we observed an interaction involving fluorescently labelled β-lactoglobulin in its native environment, i.e. cow and goat milk, for the first time. Co-elution experiments support that these β-lactoglobulin interactions occur naturally in milk and provide evidence that the interacting partners are immunoglobulins, while further sedimentation velocity experiments confirm that an interaction occurs between these molecules. The identification of these interactions, made possible through the use of fluorescence-detected analytical ultracentrifugation, provides possible clues to the long debated physiological function of this abundant milk protein.
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Affiliation(s)
- Jennifer M Crowther
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
- The Riddet Institute, Massey University, Palmerston North, New Zealand.
| | - Marita Broadhurst
- Food and Bio-Based Products, AgResearch Limited, Ruakura Research Centre, Hamilton, New Zealand
| | - Thomas M Laue
- Center To Advance Molecular Interaction Science, University of New Hampshire, Durham, NH, USA
| | - Geoffrey B Jameson
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand
- The Riddet Institute, Massey University, Palmerston North, New Zealand
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Alison J Hodgkinson
- Food and Bio-Based Products, AgResearch Limited, Ruakura Research Centre, Hamilton, New Zealand.
- On-Farm R&D, Farm Source, Fonterra Co-Operative Group, Hamilton, 3200, New Zealand.
| | - Renwick C J Dobson
- Biomolecular Interaction Centre, School of Biological Sciences, University of Canterbury, Christchurch, New Zealand.
- The Riddet Institute, Massey University, Palmerston North, New Zealand.
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Melbourne, VIC, Australia.
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42
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Varlamova EG, Zaripov OG. Beta-lactoglobulin-nutrition allergen and nanotransporter of different nature ligands therapy with therapeutic action. Res Vet Sci 2020; 133:17-25. [PMID: 32919234 DOI: 10.1016/j.rvsc.2020.08.014] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 08/08/2020] [Accepted: 08/28/2020] [Indexed: 02/06/2023]
Abstract
β-lactoglobulin is one of the nutrition allergens present in the milk of many mammals, with the exception of human. This protein belongs to the family of lipocalins, consisting of nine antiparallel β-strands (β-A to β-I) and one α-helix. This structure allows it to serve as a nanotransporter of various nature ligands in a pH dependent manner, which allows us to confidently consider it as a reliable carrier of drugs directly into the intestine, bypassing the destructive acidic environment of the stomach. Based on the latest data, this review describes the currently known methods of reducing the allergenicity of beta-lactoglobulin, as well as the mechanisms and methods of forming complexes of this protein with ligands, which emphasizes its importance and versatility and explains the growing interest in studying its properties in recent decades, and also opens up prospects for its practical application in medicine and pharmaceuticals.
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Affiliation(s)
- E G Varlamova
- Federal State Institution of Science Institute of Cell Biophysics, Russian Academy of Sciences, Institutskaya st. 3, 142290, Pushchino, Moscow Region, Russia.
| | - O G Zaripov
- Federal Science Center for Animal Husbandry named after Academy Member L.K. Ernst, Dubrovitsy village, house 60, 142132, Moscow region, Podolsky city district, Russia
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43
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Zhu J, Li K, Wu H, Li W, Sun Q. Multi-spectroscopic, conformational, and computational atomic-level insights into the interaction of β-lactoglobulin with apigenin at different pH levels. Food Hydrocoll 2020. [DOI: 10.1016/j.foodhyd.2020.105810] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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44
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Stănciuc N, Râpeanu G, Bahrim GE, Aprodu I. The Interaction of Bovine β-Lactoglobulin with Caffeic Acid: From Binding Mechanisms to Functional Complexes. Biomolecules 2020; 10:biom10081096. [PMID: 32718063 PMCID: PMC7464270 DOI: 10.3390/biom10081096] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/17/2020] [Accepted: 07/20/2020] [Indexed: 01/06/2023] Open
Abstract
In this study, the interaction of native and transglutaminase (Tgase) cross-linked β-lactoglobulin (β-LG) with caffeic acid (CA) was examined, aiming to obtain functional composites. Knowledge on the binding affinity and interaction mechanism was provided by performing fluorescence spectroscopy measurements, after heating the native and cross-linked protein at temperatures ranging from 25 to 95 °C. Regardless of the protein aggregation state, a static quenching mechanism of intrinsic fluorescence of β-LG by CA was established. The decrease of the Stern–Volmer constants with the temperature increase indicating the facile dissociation of the weakly bound complexes. The thermodynamic analysis suggested the existence of multiple contact types, such as Van der Waals’ force and hydrogen bonds, between β-LG and CA. Further molecular docking tests indicated the existence of various CA binding sites on the β-LG surface heat-treated at different temperatures. Anyway, regardless of the simulated temperature, the CA-β-LG assemblies appeared to be unstable. Compared to native protein, the CA-β-LG and CA-β-LGTgase complexes (ratio 1:1) exhibited significantly higher antioxidant activity and inhibitory effects on α-glucosidase, α-amylase, and pancreatic lipase, enzymes associated with metabolic syndrome. These findings might help the knowledge-based development of novel food ingredients with valuable biological properties.
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45
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Chanphai P, Bourassa P, Tajmir-Riahi HA. An Overview of the Loading Efficacy of Cationic Lipids with Milk Proteins: A Potential Application for Lipid Delivery. Curr Med Chem 2020; 27:4109-4117. [DOI: 10.2174/0929867325666180608122439] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2018] [Revised: 03/29/2018] [Accepted: 03/29/2018] [Indexed: 11/22/2022]
Abstract
In this review, the loading efficacies of helper and Cationic Lipids Cholesterol
(CHOL), 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), Dioctadecyl Dimethyl-
Ammonium Bromide (DDAB) and Dioleoyl Phosphatidylethanolamine (DOPE) with milk β-
lactoglobulin, α-casein and β-casein were compared in aqueous solution at physiological conditions.
Structural analysis showed that lipids bind milk proteins via hydrophilic, hydrophobic
and H-bonding contacts with DOTAP and DDAB forming more stable protein conjugates.
Loading efficacy was 30-50% and enhanced with cationic lipids. Lipid conjugation altered
protein conformation, causing a partial protein structural destabilization. Milk proteins are
capable of transporting lipids in vitro.
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Affiliation(s)
- Penprapa Chanphai
- Department de Chemistry-Biochemistry, University of Quebec a Trois-Rivieres, C.P. 500, Trois-Rivieres (Quebec) G9A 5H7, Canada
| | - Philippe Bourassa
- Department de Chemistry-Biochemistry, University of Quebec a Trois-Rivieres, C.P. 500, Trois-Rivieres (Quebec) G9A 5H7, Canada
| | - Heidar Ali Tajmir-Riahi
- Department de Chemistry-Biochemistry, University of Quebec a Trois-Rivieres, C.P. 500, Trois-Rivieres (Quebec) G9A 5H7, Canada
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Chanphai P, Tajmir-Riahi HA. Locating the binding sites of citric acid and gallic acid on milk β-lactoglobulin. J Biomol Struct Dyn 2020; 39:5160-5165. [PMID: 32579075 DOI: 10.1080/07391102.2020.1784290] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
β-Lactoglobulin (β-LG) is a member of lipocalin superfamily of transporters for small hydrophobic and hydrophilic molecules. We located the binding sites of citric acid and gallic acid on β-lactoglobulin (β-LG) in aqueous solution at physiological conditions, using spectroscopic methods, thermodynamic analysis and molecular modeling. Thermodynamic parameters ΔH0 -9.5 to -6.9 (kJ mol-1), ΔS0 23.9 to 13.6 (J mol-1K-1) and ΔG0 -14.5 to -13.6 (kJ mol-1) showed that acid binds protein via ionic contacts with gallic acid forming stronger protein conjugates consistent with theoretical modeling. Different amino acids are involved in gallic acid and citric acid complexation. Protein conformation was altered with reduction of β-sheet from 58% (free protein) to 46-43% and a major increase in α-helix from 11% (free protein) to 29-23% and random coil structure in the acid-protein, indicating a partial protein destabilization. Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- P Chanphai
- Department of Chemistry-Biochemistry-Physics, University of Québec in Trois-Rivières, Trois-Rivieres, Quebec, Canada
| | - H A Tajmir-Riahi
- Department of Chemistry-Biochemistry-Physics, University of Québec in Trois-Rivières, Trois-Rivieres, Quebec, Canada
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Xu D, Li L, Wu Y, Zhang X, Wu M, Li Y, Gai Z, Li B, Zhao D, Li C. Influence of ultrasound pretreatment on the subsequent glycation of dietary proteins. ULTRASONICS SONOCHEMISTRY 2020; 63:104910. [PMID: 31945554 DOI: 10.1016/j.ultsonch.2019.104910] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 11/07/2019] [Accepted: 11/26/2019] [Indexed: 06/10/2023]
Abstract
The influence of ultrasound treatment on the subsequent glycation process of proteins is controversial. Glycation behaviors of bovine serum albumin (BSA), β-lactoglobulin (β-Lg) and β-casein (β-CN) after ultrasound pretreatment (UP) were compared by both evaluating glycation kinetics and analyzing structural changes of proteins. UP resulted in both unfolding and aggregation behavior in protein samples, which altered the accessibility of the Lys and Arg. Five cycles of UP up-regulated the glycation degree of BSA and β-Lg, possibly due to the unfolding behavior induced by UP, which exposed additional glycation sites. In contrast, 30 cycles of UP induced a dramatic increase (by 97.9 nm) in particle size of BSA, thus burying portions of glycation sites and suppressing the glycation process. Notably, UP had minimal influence on glycation kinetics of β-CN, due to its intrinsic disordered structure. Based on proteomics analysis, the preference of Lys and Arg during glycation was found to be changed by UP in BSA and β-Lg. Four, 3 and 3 unique carboxyethylated lysine residues were identified in glycated BSA after 0, 5 and 30 cycles of UP, respectively. This study suggests that the protein glycation can be affected by UP, depending on the ultrasonication duration and native structure of the protein.
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Affiliation(s)
- Dan Xu
- College of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, China
| | - Lin Li
- College of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, China; School of Chemical Engineering and Energy Technology, Dongguan University of Technology, College Road 1, Dongguan 523808, China
| | - Yi Wu
- College of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, China
| | - Xia Zhang
- College of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, China
| | - Ming Wu
- College of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, China
| | - Yuting Li
- School of Chemical Engineering and Energy Technology, Dongguan University of Technology, College Road 1, Dongguan 523808, China
| | - Zuoqi Gai
- College of Life Science and Engineering, Foshan University, Foshan 528231, China
| | - Bing Li
- College of Food Science and Engineering, Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety, South China University of Technology, 381 Wushan Road, Tianhe District, Guangzhou 510640, China.
| | - Di Zhao
- Key Laboratory of Meat Processing and Quality Control, MOE, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Key Laboratory of Meat Products Processing, MOA, Nanjing Agricultural University, Nanjing 210095, China.
| | - Chunbao Li
- Key Laboratory of Meat Processing and Quality Control, MOE, Jiangsu Collaborative Innovation Center of Meat Production and Processing, Quality and Safety Control, Key Laboratory of Meat Products Processing, MOA, Nanjing Agricultural University, Nanjing 210095, China
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Rodzik A, Pomastowski P, Sagandykova GN, Buszewski B. Interactions of Whey Proteins with Metal Ions. Int J Mol Sci 2020; 21:ijms21062156. [PMID: 32245108 PMCID: PMC7139725 DOI: 10.3390/ijms21062156] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Revised: 03/16/2020] [Accepted: 03/18/2020] [Indexed: 12/17/2022] Open
Abstract
Whey proteins tend to interact with metal ions, which have implications in different fields related to human life quality. There are two impacts of such interactions: they can provide opportunities for applications in food and nutraceuticals, but may lead to analytical challenges related to their study and outcomes for food processing, storage, and food interactions. Moreover, interactions of whey proteins with metal ions are complicated, requiring deep understanding, leading to consequences, such as metalloproteins, metallocomplexes, nanoparticles, or aggregates, creating a biologically active system. To understand the phenomena of metal–protein interactions, it is important to develop analytical approaches combined with studies of changes in the biological activity and to analyze the impact of such interactions on different fields. The aim of this review was to discuss chemistry of β-lactoglobulin, α-lactalbumin, and lactotransferrin, their interactions with different metal ions, analytical techniques used to study them and the implications for food and nutraceuticals.
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Affiliation(s)
- Agnieszka Rodzik
- Department of Environmental Chemistry and Bioanalysis, Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100 Toruń, Poland; (A.R.); (G.N.S.); (B.B.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wileńska 4, 87-100 Toruń, Poland
| | - Paweł Pomastowski
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wileńska 4, 87-100 Toruń, Poland
- Correspondence: ; Tel.: +48-56-6114308; Fax: +48-56-6656038
| | - Gulyaim N. Sagandykova
- Department of Environmental Chemistry and Bioanalysis, Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100 Toruń, Poland; (A.R.); (G.N.S.); (B.B.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wileńska 4, 87-100 Toruń, Poland
| | - Bogusław Buszewski
- Department of Environmental Chemistry and Bioanalysis, Faculty of Chemistry, Nicolaus Copernicus University, Gagarina 7, 87-100 Toruń, Poland; (A.R.); (G.N.S.); (B.B.)
- Centre for Modern Interdisciplinary Technologies, Nicolaus Copernicus University, Wileńska 4, 87-100 Toruń, Poland
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49
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Cortes-Hernandez P, Vázquez Nuñez R, Domínguez-Ramírez L. Docking and Molecular Dynamics Predictions of Pesticide Binding to the Calyx of Bovine β-Lactoglobulin. Int J Mol Sci 2020; 21:ijms21061988. [PMID: 32183317 PMCID: PMC7139891 DOI: 10.3390/ijms21061988] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 03/01/2020] [Accepted: 03/02/2020] [Indexed: 11/16/2022] Open
Abstract
Pesticides are used extensively in agriculture, and their residues in food must be monitored to prevent toxicity. The most abundant protein in cow’s milk, β-lactoglobulin (BLG), shows high affinity for diverse hydrophobic ligands in its central binding pocket, called the calyx. Several of the most frequently used pesticides are hydrophobic. To predict if BLG may be an unintended carrier for pesticides, we tested its ability to bind 555 pesticides and their isomers, for a total of 889 compounds, in a rigid docking screen. We focused on the analysis of 60 unique molecules belonging to the five pesticide classes defined by the World Health Organization, that docked into BLG’s calyx with ΔGs ranging from −8.2 to −12 kcal mol−1, chosen by statistical criteria. These “potential ligands” were further analyzed using molecular dynamic simulations, and the binding energies were explored with Molecular Mechanics/Generalized Born/Surface Area (MMGBSA). Hydrophobic pyrethroid insecticides, like cypermethrin, were found to bind as deeply and tightly into the calyx as BLG’s natural ligand, palmitate; while polar compounds, like paraquat, were expelled. Our results suggest that BLG could be a carrier for pesticides, in particular for pyrethroid insecticides, allowing for their accumulation in cow’s milk beyond their solubility restrictions. This analysis opens possibilities for pesticide biosensor design based on BLG.
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Affiliation(s)
- Paulina Cortes-Hernandez
- Instituto Mexicano del Seguro Social (IMSS), Centro de Investigación Biomédica de Oriente (CIBIOR), Cellular Biology Laboratory, 74360 Metepec, Puebla, Mexico;
| | - Roberto Vázquez Nuñez
- Department of Fundamental Microbiology, University of Lausanne, CH-1015 Lausanne, Switzerland;
| | - Lenin Domínguez-Ramírez
- Department of Chemical and Biological Sciences, School of Sciences, Universidad de las Américas Puebla, Santa Catarina Mártir Cholula, 72810 San Andrés Cholula, Puebla, Mexico
- Correspondence:
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Bonarek P, Loch JI, Tworzydło M, Cooper DR, Milto K, Wróbel P, Kurpiewska K, Lewiński K. Structure-based design approach to rational site-directed mutagenesis of β-lactoglobulin. J Struct Biol 2020; 210:107493. [PMID: 32169624 DOI: 10.1016/j.jsb.2020.107493] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 03/06/2020] [Accepted: 03/09/2020] [Indexed: 12/30/2022]
Abstract
Recombinant proteins play an important role in medicine and have diverse applications in industrial biotechnology. Lactoglobulin has shown great potential for use in targeted drug delivery and body fluid detoxification because of its ability to bind a variety of molecules. In order to modify the biophysical properties of β-lactoglobulin, a series of single-site mutations were designed using a structure-based approach. A 3-dimensional structure alignment of homologous molecules led to the design of nine β-lactoglobulin variants with mutations introduced in the binding pocket region. Seven stable and correctly folded variants (L39Y, I56F, L58F, V92F, V92Y, F105L, M107L) were thoroughly characterized by fluorescence, circular dichroism, isothermal titration calorimetry, size-exclusion chromatography, and X-ray structural investigations. The effects of the amino acid substitutions were observed as slight rearrangements of the binding pocket geometry, but they also significantly influenced the global properties of the protein. Most of the mutations increased the thermal/chemical stability without altering the dimerization constant or pH-dependent conformational behavior. The crystal structures reveal that the I56F and F105L mutations reduced the depth of the binding pocket, which is advantageous since it can reduce the affinity to endogenous fatty acids. The F105L mutant created a unique binding mode for a fatty acid, supporting the idea that lactoglobulin can be altered to bind unique molecules. Selected variants possessing a unique combination of their individual properties can be used for further, more advanced mutagenesis, and the presented results support further research using β-lactoglobulin as a therapeutic delivery agent or a blood detoxifying molecule.
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Affiliation(s)
- Piotr Bonarek
- Jagiellonian University, Faculty of Biochemistry, Biophysics and Biotechnology, Gronostajowa 7, 30-387 Kraków, Poland
| | - Joanna I Loch
- Jagiellonian University, Faculty of Chemistry, Gronostajowa 2, 30-387 Kraków, Poland
| | - Magdalena Tworzydło
- Jagiellonian University, Faculty of Biochemistry, Biophysics and Biotechnology, Gronostajowa 7, 30-387 Kraków, Poland
| | - David R Cooper
- University of Virginia, Department of Molecular Physiology and Biological Physics, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
| | - Katažyna Milto
- Jagiellonian University, Faculty of Biochemistry, Biophysics and Biotechnology, Gronostajowa 7, 30-387 Kraków, Poland
| | - Paulina Wróbel
- Jagiellonian University, Faculty of Chemistry, Gronostajowa 2, 30-387 Kraków, Poland
| | - Katarzyna Kurpiewska
- Jagiellonian University, Faculty of Chemistry, Gronostajowa 2, 30-387 Kraków, Poland
| | - Krzysztof Lewiński
- Jagiellonian University, Faculty of Chemistry, Gronostajowa 2, 30-387 Kraków, Poland.
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