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Adebayo MA, Kolawole AN, Falese BA, Kolawole AO. Spectroscopic and in silico evaluation of hesperetin, aglycone flavanone, as a prospective regulatory ligand for human salivary α-amylase. J Biomol Struct Dyn 2024; 42:3177-3192. [PMID: 37382217 DOI: 10.1080/07391102.2023.2225621] [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: 08/29/2022] [Accepted: 05/01/2023] [Indexed: 06/30/2023]
Abstract
The insight into the binding mechanism of hesperetin, an aglycone flavanone, with human salivary α-amylase (HSAA), simulated under physiological salivary condition, was explored using various spectroscopic approaches and in silico method. Hesperetin effectively quenched the intrinsic fluorescence of HSAA and the quenching was mixed quenching mechanism. The interaction perturbed the HSAA intrinsic fluorophore microenvironment and the enzyme global surface hydrophobicity. The negative values of ΔG for thermodynamic parameters and in silico study revealed the spontaneity of HSAA-hesperetin complex while the positive values of enthalpy change (ΔH) and entropy change (ΔS) showed noticeable involvement of hydrophobic bonding in the stabilization of the complex. Hesperetin was a mixed inhibitor for HSAA with a KI of 44.60 ± 1.63 μM and having apparent inhibition coefficient (α) of 0.26. Macromolecular crowding, given rise to microviscosity and anomalous diffusion, regulated the interaction. Sodium ion (Na+) created high ionic strength, also, modulated the interaction. The in silico study proposed the preferential binding of hesperetin at the active cleft domain of HSAA with the least energy of -8.0 kcal/mol. This work gives a novel insight on the potentials of hesperetin as a future prospective medicinal candidate in the management of postprandial hyperglycemic condition.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Masaudat A Adebayo
- Department of Science Laboratory Technology (Biochemistry Option), School of Science and Technology, Federal Polytechnic, Ede, Osun State, Nigeria
| | - Adejoke N Kolawole
- Biomolecular Structure and Dynamics Unit, Department of Biochemistry, The Federal University of Technology, Akure, Nigeria
| | - Babatunde A Falese
- Biomolecular Structure and Dynamics Unit, Department of Biochemistry, The Federal University of Technology, Akure, Nigeria
| | - Ayodele O Kolawole
- Biomolecular Structure and Dynamics Unit, Department of Biochemistry, The Federal University of Technology, Akure, Nigeria
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2
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Falese BA, Kolawole AN, Sarumi OA, Kolawole AO. Probing the interaction of iminium form of sanguinarine with human salivary α-amylase by multi-spectroscopic techniques and molecular docking. J Mol Liq 2021. [DOI: 10.1016/j.molliq.2021.116346] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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3
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Xia Q, Akanbi TO, Wang B, Li R, Liu S, Barrow CJ. Investigation of enhanced oxidation stability of microencapsulated enzymatically produced tuna oil concentrates using complex coacervation. Food Funct 2020; 11:10748-10757. [PMID: 33231232 DOI: 10.1039/d0fo02350g] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Tuna oil was selectively hydrolysed using Thermomyces lanuginosus lipase for 6 h to prepare omega-3 acylglycerol concentrate with the DHA content significantly increased from 24.9% in tuna oil to 36.3% in the acylglycerol concentrate. The acylglycerol concentrate was subsequently encapsulated into the "multi-core" microcapsules using gelatin-sodium hexametaphosphate complex coacervates as the shell material. Rancimat, Oxipres and thermogravimetric analyses all showed that the microencapsulated acylglycerol concentrate had unexpectedly improved oxidation stability, compared to those produced using tuna oil, even though the concentrated oils themselves were significantly less stable than tuna oil. The incorporation of enzymatic tuna oil acylglycerol concentrate also significantly improved the oxidation stability of microencapsulated standard refined unconcentrated tuna oil. A wide range of characteristics including lipid and fatty acid composition, oil-in-water (O/W) emulsion properties, morphology, nanomechanical strength and physicochemical stability of acylglycerol, acylglycerol oil-in-water (O/W) emulsion and final microcapsules were investigated throughout the preparation. The result suggests that high levels of monoacylglycerol (about 35%) and diacylglycerol (about 8.5%) were produced in the acylglycerol. The acylglycerol O/W emulsion exhibited significantly smaller droplet size, lower zeta-potential and higher surface hydrophobicity, which contributed to the formation of the microcapsule with a significantly smoother surface and more compact structure, finally leading to improved oxidative stability compared to those prepared from native tuna oil.
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Affiliation(s)
- Qiuyu Xia
- College of Food Science and Technology, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety, Zhanjiang 524088, China.
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4
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Xia Q, Akanbi TO, Wang B, Li R, Yang W, Barrow CJ. Investigating the Mechanism for the Enhanced Oxidation Stability of Microencapsulated Omega-3 Concentrates. Mar Drugs 2019; 17:md17030143. [PMID: 30823458 PMCID: PMC6471227 DOI: 10.3390/md17030143] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 02/15/2019] [Accepted: 02/22/2019] [Indexed: 11/16/2022] Open
Abstract
Enzymatically concentrated anchovy oil (concentrate) is known to be much less stable than unconcentrated anchovy oil. However, we previously showed that concentrate surprisingly forms more stable microcapsules, when produced by complex coacervation, than does unconcentrated anchovy oil. Here we investigate the mechanism of this unexpected stability. We also investigate whether or not incorporation of concentrate can be used as an additive to improve the stability of unconcentrated anchovy oil microcapsules. Results showed that microcap stability increased as the amount of added concentrate increased. Decreased emulsion droplet size, lower positively charged zeta potential, and higher surface hydrophobicity were observed in the oil/water (O/W) emulsion, with the incorporation of concentrate in the oil phase, compared with the unconcentrated anchovy oil O/W emulsion. Both the decreased zeta potential and the increased hydrophobicity of concentrate in the mixed oil phase may improve droplet agglomeration, leading to enhanced oxidative stability of the concentrate-containing microcapsules. Decreased repulsive forces between droplets result in a more compact structure, thicker outer shell, and smoother surface, resulting in enhanced oxidation stability of the concentrate-containing microcapsules.
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Affiliation(s)
- Qiuyu Xia
- Coconuts Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang 571339, China.
| | - Taiwo O Akanbi
- Centre for Chemistry and Biotechnology, Deakin University, Geelong, VIC 3217, Australia.
| | - Bo Wang
- Nu-Mega Ingredients Pty Ltd., Brisbane, QLD 4113, Australia.
| | - Rui Li
- Coconuts Research Institute, Chinese Academy of Tropical Agricultural Sciences, Wenchang 571339, China.
| | - Wenrong Yang
- Centre for Chemistry and Biotechnology, Deakin University, Geelong, VIC 3217, Australia.
| | - Colin J Barrow
- Centre for Chemistry and Biotechnology, Deakin University, Geelong, VIC 3217, Australia.
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5
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Deshpande M, Sathe SK. Interactions with 8-Anilinonaphthalene-1-sulfonic Acid (ANS) and Surface Hydrophobicity of Black Gram (Vigna mungo) Phaseolin. J Food Sci 2018; 83:1847-1855. [PMID: 29928765 DOI: 10.1111/1750-3841.14204] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/22/2018] [Accepted: 04/27/2018] [Indexed: 11/27/2022]
Abstract
Surface hydrophobicity (SH) properties of the trimeric storage protein phaseolin (black gram phaseolin [BGP]) of black gram (Vigna mungo) were investigated using 8-anilinonaphthalene-1-sulfonate (ANS) as an extrinsic fluorescent probe. The emission maxima of fluorescence spectra of BGP:ANS complex were blue-shifted to 455 nm as compared to 515 nm for the free ANS. Saturation binding occurred at a dye-to-protein ratio of about 30:1. The quantum yield of the complex increased with increasing ionic strength. The Kd values were 1.7 × 10-5 and 1.37 × 10-5 M using fractional occupancy and Scatchard analysis, respectively. Analysis of the binding data using Klotz plot revealed 4 binding sites/protomer. SH of BGP was 48%, which rapidly decreased due to the perturbation of the binding sites as the protein unfolded in GdnHCl and urea. By varying processing conditions, it may be possible to alter the surface exposure of SH of BGP to extend its applications in novel food products with desired textural attributes. PRACTICAL APPLICATION Varying solvent and/or processing conditions can assist to modulate the surface hydrophobicity of functional legume proteins to achieve desired textural properties in the end product.
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Affiliation(s)
- Maithili Deshpande
- Dept. of Chemical Engineering, Natl. Inst. of Technology Karnataka, Surathkal, 575025, India.,Dept. of Chemical and Biomolecular Engineering, 120 Olin Hall, Cornell University, Ithaca, NY, 14853, U.S.A
| | - S K Sathe
- Dept. of Nutrition, Food & Exercise Sciences, Florida State University, Tallahassee, FL, 32306-1493, U.S.A
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Sidorin EV, Khomenko VA, Kim NY, Dmitrenok PS, Stenkova AM, Novikova OD, Solov'eva TF. Self-Organization of Recombinant Membrane Porin OmpF from Yersinia pseudotuberculosis in Aqueous Environments. BIOCHEMISTRY (MOSCOW) 2017; 82:1304-1313. [PMID: 29223157 DOI: 10.1134/s0006297917110086] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Recombinant porin OmpF (an integral protein of bacterial outer membrane) from Yersinia pseudotuberculosis was synthesized in Escherichia coli cells as inclusion bodies. By combining the methods of anion-exchange and gel filtration chromatographies, recombinant OmpF (rOmpF) was isolated as an individual protein in its denatured state, and its characteristic properties (molecular mass, N-terminal amino acid sequence, and hydrodynamic radius of the protein in 8 M urea solution) were determined. According to the data of gel filtration, dynamic light scattering, optical spectroscopy, and binding of the hydrophobic fluorescent probe 8-anilino-1-naphthalenesulfonic acid, the rOmpF is fully unfolded in 8 M urea and exists in random coil conformation. In aqueous solutions, rOmpF undergoes conformational changes, reversible self-association, and aggregation. When transferred from 8 M urea into water, PBS (containing 0.15 M NaCl, pH 7.4), or buffer containing 0.8 M urea (pH 8.0), fully unfolded rOmpF forms relatively compact monomeric intermediates prone to self-association with formation of multimers. The oligomeric intermediates have high content of native protein-like secondary structure and pronounced tertiary structure. In acidic media (pH 5.0, close to the protein isoelectric point), rOmpF undergoes rapid irreversible aggregation. Therefore, we found that medium composition significantly affects both porin folding and processes of its self-association and aggregation.
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Affiliation(s)
- E V Sidorin
- Elyakov Pacific Institute of Bioorganic Chemistry, Far-Eastern Branch of the Russian Academy of Sciences, Vladivostok, 690022, Russia.
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7
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Jansens KJA, Brijs K, Stetefeld J, Delcour JA, Scanlon MG. Ultrasonic Characterization of Amyloid-Like Ovalbumin Aggregation. ACS OMEGA 2017; 2:4612-4620. [PMID: 31457750 PMCID: PMC6641891 DOI: 10.1021/acsomega.7b00366] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Accepted: 06/29/2017] [Indexed: 06/10/2023]
Abstract
Thermal processing conditions, pH, and salt content affect the formation of egg white ovalbumin amyloid, which was investigated using high-precision measurements of ultrasonic velocity and attenuation. These were related to fluorescence and particle size measurements. Fluorescence changes indicated the formation of amyloid-like aggregates that was enhanced by increasing time-temperature treatments. The ultrasonic velocity of ovalbumin after heating at neutral pH (60 min at 70 or 80 °C) was lower than that of unheated ovalbumin, whereas the attenuation was higher. The decrease in the velocity represents increased compressibility associated with a change in the compactness of the protein, whereas changes in attenuation are due to protein conformational changes. Heating ramp studies revealed transitions at approximately 58 and 73 °C. During heating at a constant temperature, the ultrasonic velocity decreased slowly with increasing heating time, indicating an increase in ovalbumin compressibility. It is suggested that the obtained amyloid-like ovalbumin aggregates contain a compact core surrounded by loosely packed protein segments.
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Affiliation(s)
- Koen J. A. Jansens
- Laboratory
of Food Chemistry and Biochemistry, Leuven
Food Science and Nutrition Research Centre (LFoRCe), KU Leuven Kasteelpark Arenberg 20, B-3001 Leuven, Belgium
| | - Kristof Brijs
- Laboratory
of Food Chemistry and Biochemistry, Leuven
Food Science and Nutrition Research Centre (LFoRCe), KU Leuven Kasteelpark Arenberg 20, B-3001 Leuven, Belgium
| | - Jörg Stetefeld
- Department
of Chemistry, University of Manitoba, Winnipeg, Canada R2T 2N2
| | - Jan A. Delcour
- Laboratory
of Food Chemistry and Biochemistry, Leuven
Food Science and Nutrition Research Centre (LFoRCe), KU Leuven Kasteelpark Arenberg 20, B-3001 Leuven, Belgium
| | - Martin G. Scanlon
- Department
of Food Science, University of Manitoba, Winnipeg, Manitoba, Canada R3T 2N2
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8
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Chanphai P, Agudelo D, Tajmir-Riahi HA. PEG and mPEG-anthracene conjugate with trypsin and trypsin inhibitor: hydrophobic and hydrophilic contacts. J Biomol Struct Dyn 2017; 35:2257-2268. [PMID: 27434220 DOI: 10.1080/07391102.2016.1214621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 07/14/2016] [Indexed: 12/23/2022]
Abstract
The conjugation of trypsin (try) and trypsin inhibitor (tryi) with poly(ethylene glycol) (PEG) and methoxypoly(ethylene glycol) anthracene (mPEG-anthracene) was investigated in aqueous solution, using multiple spectroscopic methods, thermodynamic analysis, and molecular modeling. Thermodynamic parameters ΔS, ΔH, and ΔG showed protein-PEG bindings occur via H-bonding and van der Waals contacts with trypsin inhibitor forming more stable conjugate than trypsin. As polymer size increased more stable PEG-protein conjugate formed, while hydrophobic mPEG-anthracene forms less stable protein complexes. Modeling showed the presence of several H-bonding contacts between polymer and amino acids that stabilize protein-polymer conjugation. Polymer complexation induces more perturbations of trypsin inhibitor structure than trypsin with reduction of protein alpha-helix and major increase in random structures, indicating protein structural destabilization.
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Affiliation(s)
- P Chanphai
- a Department of Chemistry-Biochemistry and Physics , University of Québec at Trois-Rivières , C. P. 500, Trois-Rivieres G9A 5H7 , Quebec , Canada
| | - D Agudelo
- a Department of Chemistry-Biochemistry and Physics , University of Québec at Trois-Rivières , C. P. 500, Trois-Rivieres G9A 5H7 , Quebec , Canada
| | - H A Tajmir-Riahi
- a Department of Chemistry-Biochemistry and Physics , University of Québec at Trois-Rivières , C. P. 500, Trois-Rivieres G9A 5H7 , Quebec , Canada
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9
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Chanphai P, Tajmir-Riahi H. Trypsin and trypsin inhibitor bind milk beta-lactoglobulin: Protein–protein interactions and morphology. Int J Biol Macromol 2017; 96:754-758. [DOI: 10.1016/j.ijbiomac.2016.12.075] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 12/21/2016] [Accepted: 12/29/2016] [Indexed: 11/16/2022]
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10
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Chanphai P, Kreplak L, Tajmir-Riahi HA. Aggregation of trypsin and trypsin inhibitor by Al cation. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2017; 169:7-12. [PMID: 28246055 DOI: 10.1016/j.jphotobiol.2017.02.018] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Revised: 02/16/2017] [Accepted: 02/21/2017] [Indexed: 11/26/2022]
Abstract
Al cation may trigger protein structural changes such as aggregation and fibrillation, causing neurodegenerative diseases. We report the effect of Al cation on the solution structures of trypsin (try) and trypsin inhibitor (tryi), using thermodynamic analysis, UV-Visible, Fourier transform infrared (FTIR) spectroscopic methods and atomic force microscopy (AFM). Thermodynamic parameters showed Al-protein bindings occur via H-bonding and van der Waals contacts for trypsin and trypsin inhibitor. AFM showed that Al cations are able to force trypsin into larger or more robust aggregates than trypsin inhibitor, with trypsin 5±1 SE (n=52) proteins per aggregate and for trypsin inhibitor 8.3±0.7 SE (n=118). Thioflavin T test showed no major protein fibrillation in the presence of Al cation. Al complexation induced more alterations of trypsin inhibitor conformation than trypsin.
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Affiliation(s)
- P Chanphai
- Department of Chemistry-Biochemistry, Physics University of Québec, Trois-Rivières, C. P. 500, TR, Quebec G9A 5H7, Canada
| | - L Kreplak
- Department of Physics and Atmospheric Science, Sir James Dunn Building Dalhousie University, Lord Dalhousie Drive, Halifax NS B3H 4R2, Canada
| | - H A Tajmir-Riahi
- Department of Chemistry-Biochemistry, Physics University of Québec, Trois-Rivières, C. P. 500, TR, Quebec G9A 5H7, Canada.
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11
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Jansens KJ, Brijs K, Delcour JA, Scanlon MG. Amyloid-like aggregation of ovalbumin: Effect of disulfide reduction and other egg white proteins. Food Hydrocoll 2016. [DOI: 10.1016/j.foodhyd.2016.07.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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12
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Lambrecht MA, Rombouts I, De Ketelaere B, Delcour JA. Prediction of heat-induced polymerization of different globular food proteins in mixtures with wheat gluten. Food Chem 2016; 221:1158-1167. [PMID: 27979074 DOI: 10.1016/j.foodchem.2016.11.043] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/11/2016] [Accepted: 11/08/2016] [Indexed: 11/16/2022]
Abstract
Egg, soy or whey protein co-exists with wheat gluten in different food products. Different protein types impact each other during heat treatment. A positive co-protein effect occurs when heat-induced polymerization of a mixture of proteins is more intense than that of the isolated proteins. The intrinsic protein characteristics of globular proteins which enhance polymerization in mixtures with gluten are unknown. In this report, a model was developed to predict potential co-protein effects in mixtures of gluten and globular proteins during heating at 100°C. A negative co-protein effect with addition of lysozyme, no co-protein effect with soy glycinin or egg yolk and positive co-protein effects with bovine serum albumin, (S-)ovalbumin, egg white, whole egg, defatted egg yolk, wheat albumins and wheat globulins were detected. The level of accessible free sulfhydryl groups and the surface hydrophobicity of unfolded globular proteins were the main characteristics in determining the co-protein effects in gluten mixtures.
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Affiliation(s)
- Marlies A Lambrecht
- KU Leuven, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
| | - Ine Rombouts
- KU Leuven, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
| | - Bart De Ketelaere
- KU Leuven, Department of Biosystems, Kasteelpark Arenberg 30, B-3001 Heverlee, Belgium.
| | - Jan A Delcour
- KU Leuven, Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), Kasteelpark Arenberg 20, B-3001 Leuven, Belgium.
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13
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Chanphai P, Tajmir-Riahi H. Chitosan nanoparticles conjugate with trypsin and trypsin inhibitor. Carbohydr Polym 2016; 144:346-52. [DOI: 10.1016/j.carbpol.2016.02.066] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2016] [Revised: 02/15/2016] [Accepted: 02/22/2016] [Indexed: 01/23/2023]
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14
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Ali M, Kumar A, Kumar M, Pandey BN. The interaction of human serum albumin with selected lanthanide and actinide ions: Binding affinities, protein unfolding and conformational changes. Biochimie 2016; 123:117-29. [PMID: 26821345 DOI: 10.1016/j.biochi.2016.01.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Accepted: 01/22/2016] [Indexed: 10/22/2022]
Abstract
Human serum albumin (HSA), the most abundant soluble protein in blood plays critical roles in transportation of biomolecules and maintenance of osmotic pressure. In view of increasing applications of lanthanides- and actinides-based materials in nuclear energy, space, industries and medical applications, the risk of exposure with these metal ions is a growing concern for human health. In present study, binding interaction of actinides/lanthanides [thorium: Th(IV), uranium: U(VI), lanthanum: La(III), cerium: Ce(III) and (IV)] with HSA and its structural consequences have been investigated. Ultraviolet-visible, Fourier transform-infrared, Raman, Fluorescence and Circular dichroism spectroscopic techniques were applied to study the site of metal ions interaction, binding affinity determination and the effect of metal ions on protein unfolding and HSA conformation. Results showed that these metal ions interacted with carbonyl (CO..:)/amide(N..-H) groups and induced exposure of aromatic residues of HSA. The fluorescence analysis indicated that the actinide binding altered the microenvironment around Trp214 in the subdomain IIA. Binding affinity of U(VI) to HSA was slightly higher than that of Th(IV). Actinides and Ce(IV) altered the secondary conformation of HSA with a significant decrease of α-helix and an increase of β-sheet, turn and random coil structures, indicating a partial unfolding of HSA. A correlation was observed between metal ion's ability to alter HSA conformation and protein unfolding. Both cationic effects and coordination ability of metal ions seemed to determine the consequences of their interaction with HSA. Present study improves our understanding about the protein interaction of these heavy ions and their impact on its secondary structure. In addition, binding characteristics may have important implications for the development of rational antidote for the medical management of health effects of actinides and lanthanides.
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Affiliation(s)
- Manjoor Ali
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 85, India
| | - Amit Kumar
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 85, India.
| | - Mukesh Kumar
- Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 85, India
| | - Badri N Pandey
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 85, India
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15
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Chanphai P, Tajmir-Riahi H. Trypsin and trypsin inhibitor bind PAMAM nanoparticles: Effect of hydrophobicity on protein–polymer conjugation. J Colloid Interface Sci 2016; 461:419-424. [DOI: 10.1016/j.jcis.2015.09.048] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Revised: 09/20/2015] [Accepted: 09/21/2015] [Indexed: 12/20/2022]
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16
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17
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Relating the variation of secondary structure of gelatin at fish oil–water interface to adsorption kinetics, dynamic interfacial tension and emulsion stability. Food Chem 2014; 143:484-91. [DOI: 10.1016/j.foodchem.2013.07.130] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Revised: 07/08/2013] [Accepted: 07/29/2013] [Indexed: 11/22/2022]
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18
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Haque MA, Aldred P, Chen J, Barrow CJ, Adhikari B. Comparative study of denaturation of whey protein isolate (WPI) in convective air drying and isothermal heat treatment processes. Food Chem 2013; 141:702-11. [DOI: 10.1016/j.foodchem.2013.03.035] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Revised: 02/01/2013] [Accepted: 03/11/2013] [Indexed: 10/27/2022]
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19
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Rather GM, Gupta MN. Three phase partitioning leads to subtle structural changes in proteins. Int J Biol Macromol 2013; 60:134-40. [DOI: 10.1016/j.ijbiomac.2013.05.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 05/02/2013] [Accepted: 05/18/2013] [Indexed: 11/28/2022]
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20
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Rather GM, Gupta MN. Refolding of urea denatured ovalbumin with three phase partitioning generates many conformational variants. Int J Biol Macromol 2013; 60:301-8. [DOI: 10.1016/j.ijbiomac.2013.06.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 06/06/2013] [Accepted: 06/10/2013] [Indexed: 10/26/2022]
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21
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Timchenko AA, Novosylna OV, Prituzhalov EA, Kihara H, El’skaya AV, Negrutskii BS, Serdyuk IN. Different Oligomeric Properties and Stability of Highly Homologous A1 and Proto-Oncogenic A2 Variants of Mammalian Translation Elongation Factor eEF1. Biochemistry 2013; 52:5345-53. [DOI: 10.1021/bi400400r] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
| | - Oleksandra V. Novosylna
- State Key Laboratory of Molecular
and Cellular Biology, Institute of Molecular Biology and Genetics, NAS of Ukraine, Kiev 03680, Ukraine
| | | | - Hiroshi Kihara
- Department of Physics, Kansai Medical University, Hirakata, Osaka 573-1136,
Japan
| | - Anna V. El’skaya
- State Key Laboratory of Molecular
and Cellular Biology, Institute of Molecular Biology and Genetics, NAS of Ukraine, Kiev 03680, Ukraine
| | - Boris S. Negrutskii
- State Key Laboratory of Molecular
and Cellular Biology, Institute of Molecular Biology and Genetics, NAS of Ukraine, Kiev 03680, Ukraine
| | - Igor N. Serdyuk
- Institute of Protein Research, RAS, Pushchino 142290, Russia
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22
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Rather GM, Mukherjee J, Halling PJ, Gupta MN. Activation of alpha chymotrypsin by three phase partitioning is accompanied by aggregation. PLoS One 2012; 7:e49241. [PMID: 23239966 PMCID: PMC3519768 DOI: 10.1371/journal.pone.0049241] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2012] [Accepted: 10/05/2012] [Indexed: 11/18/2022] Open
Abstract
Precipitation of alpha chymotrypsin in the simultaneous presence of ammonium sulphate and t-butanol (three phase partitioning) resulted in preparations which showed self aggregation of the enzyme molecules. Precipitation with increasing amounts of ammonium sulphate led to increasing size of aggregates. While light scattering estimated the hydrodynamic diameter of these aggregates in the range of 242-1124 nm; Nanoparticle tracking analysis (NTA) gave the value as 130-462 nm. Scanning electron microscopy and gel filtration on Sephadex G-200 showed extensive aggregation in these preparations. Transmission electron microscopy showed that the aggregates had irregular shapes. All the aggregates had about 3× higher catalytic activity than the native enzyme. These aggregates did not differ in λ(max) of fluorescence emission which was around 340 nm. However, all the aggregates showed higher fluorescence emission intensity. Far-UV and near-UV circular dichroism also showed no significant structural changes as compared to the native molecule. Interestingly, HPLC gel filtration (on a hydroxylated silica column) gave 14 nm as the diameter for all preparations. Light scattering of preparations in the presence of 10% ethylene glycol also dissociated the aggregates to monomers of 14 nm. Both these results indicated that hydrophobic interactions were the driving force behind this aggregation. These results indicate: (1) Even without any major structural change, three phase partitioning led to protein molecules becoming highly prone to aggregation. (2) Different methods gave widely different estimates of sizes of aggregates. It was however possible to reconcile the data obtained with various approaches. (3) The nature of the gel filtration column is crucial and use of this technique for refolding and studying aggregation needs a rethink.
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Affiliation(s)
- Gulam Mohmad Rather
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Joyeeta Mukherjee
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
| | - Peter James Halling
- Department of Pure and Applied Chemistry, University of Strathclyde, Scotland, United Kingdom
| | - Munishwar Nath Gupta
- Chemistry Department, Indian Institute of Technology Delhi, Hauz Khas, New Delhi, India
- * E-mail:
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23
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Interfacial and emulsifying properties of lentil protein isolate. Food Chem 2012; 134:1343-53. [DOI: 10.1016/j.foodchem.2012.03.029] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 02/08/2012] [Accepted: 03/06/2012] [Indexed: 11/23/2022]
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24
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Effect of Methylglyoxal Modification of Human α-Crystallin on the Structure, Stability and Chaperone Function. Protein J 2010; 29:551-6. [DOI: 10.1007/s10930-010-9289-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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25
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Lamba J, Paul S, Hasija V, Aggarwal R, Chaudhuri TK. Monitoring protein folding and unfolding pathways through surface hydrophobicity changes using fluorescence and circular dichroism spectroscopy. BIOCHEMISTRY (MOSCOW) 2009; 74:393-8. [DOI: 10.1134/s0006297909040063] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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26
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Paul S, Kundu M, Das KP, Mishra S, Chaudhuri TK. Unfolding studies of Escherichia coli maltodextrin glucosidase monitored by fluorescence spectroscopy. J Biol Phys 2008; 34:539-50. [PMID: 19669512 DOI: 10.1007/s10867-008-9117-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2008] [Accepted: 09/11/2008] [Indexed: 11/24/2022] Open
Abstract
Equilibrium unfolding of a 69-kDa monomeric Escherichia coli maltodextrin glucosidase (MalZ) was studied using intrinsic and extrinsic fluorescence spectroscopy. The unfolding transition of MalZ followed a three-state process, involving the formation of a stable intermediate state having more exposed hydrophobic surface. It was found that the protein structure can be easily perturbed by low concentration of guanidium hydrochloride (GdnHCl) and, at a GdnHCl concentration of 2 M, MalZ was denatured completely. The active site of the protein also has been proved to be sensitive to a low concentration of GdnHCl since MalZ deactivated at 0.5 M GdnHCl completely. The surface hydrophobicity and ANS-binding site of the protein have been determined to be 150.7 and 0.24, respectively. Perhaps the formation of the stable unfolding intermediate, having higher surface hydrophobicity, may be one of the reasons for aggregation of MalZ and its recognition by chaperonin GroEL during the assisted folding pathway.
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Affiliation(s)
- Subhankar Paul
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
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27
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Hiller B, Lorenzen PC. Surface hydrophobicity of physicochemically and enzymatically treated milk proteins in relation to techno-functional properties. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2008; 56:461-468. [PMID: 18163564 DOI: 10.1021/jf072400c] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Surface hydrophobicity (SH) of milk proteins treated physicochemically (by heating and Maillard reaction) or modified enzymatically (by transglutaminase, lactoperoxidase, laccase, and glucose oxidase) was assessed in relation to their techno-functional properties. Heat-treatment increased SH of whey protein isolate and decreased SH of sodium caseinate and bovine serum albumin. Maillard reaction of milk proteins caused time-depended decreases of SH. Only for total milk protein reacting with glucose and lactose elevated SH-values were detected. Protein modification with transglutaminase, laccase, and lactoperoxidase strongly increased the SH of whey protein isolate and total milk protein. Incubation with glucose oxidase elevated SH values of sodium caseinate, whey protein isolate, and total milk protein. When correlating SH with techno-functional properties, a positive correlation was observed between SH and foam formation, and a negative correlation was observed between SH and foam stability as well as emulsion stability. No clear correlation was detected between SH and emulsifying activity, surface tension, viscosity, and heat stability of enzymatically and physicochemically treated milk proteins.
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Affiliation(s)
- Beate Hiller
- Institute of Dairy Chemistry and Technology, Federal Research Centre for Nutrition and Food, Location Kiel, Hermann-Weigmann-Strasse 1, D-24103 Kiel, Germany
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28
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Kundu M, Sen PC, Das KP. Structure, stability, and chaperone function of αA-crystallin: Role of N-terminal region. Biopolymers 2007; 86:177-92. [PMID: 17345631 DOI: 10.1002/bip.20716] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Small heat shock protein alphaA-crystallin, the major protein of the eye lens, is a molecular chaperone. It consists of a highly conserved central domain flanked by the N-terminal and C-terminal regions. In this article we studied the role of the N-terminal domain in the structure and chaperone function of alphaA-crystallin. Using site directed truncation we raised several deletion mutants of alphaA-crystallin and their protein products were expressed in Escherichia coli. Size exclusion chromatography of these purified proteins showed that deletion from the N-terminal beyond the first 20 residues drastically reduced the oligomeric association of alphaA-crystallin and its complete removal resulted in a tetramer. Chaperone activity of alphaA-crystallin, determined by thermal and nonthermal aggregation and refolding assay, decreased with increasing length of deletion and little activity was observed for the tetramer. However it was revealed that N-terminal regions were not responsible for specific recognition of natural substrates and that low affinity substrate binding sites existed in other part of the molecule. The number of exposed hydrophobic sites and the affinity of binding hydrophobic probe bis-ANS as well as protein substrates decreased with N-terminal deletion. The stability of the mutant proteins decreased with increase in the length of deletion. The role of thermodynamic stability, oligomeric size, and surface hydrophobicity in chaperone function is discussed. Detailed analysis showed that the most important role of N-terminal region is to control the oligomerization, which is crucial for the stability and in vivo survival of this protein molecule.
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Affiliation(s)
- Madhuchhanda Kundu
- Protein Chemistry Laboratory, Department of Chemistry, Bose Institute, 93/1 A.P.C. Road, Kolkata 700 009, India
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29
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Sugahara T, Yamada Y, Yano S, Sasaki T. Heat denaturation enhanced immunoglobulin production stimulating activity of lysozyme from hen egg white. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1572:19-24. [PMID: 12204328 DOI: 10.1016/s0304-4165(02)00272-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Lysozyme from hen egg white was identified as an immunoglobulin production stimulating factor (IPSF) that enhances immunoglobulin production by hybridomas and lymphocytes. The IPSF activity of lysozyme was facilitated by heat treatment. The heat treatment of lysozyme at 83 degrees C for 30 min activated its specific IPSF effect 30.0-fold compared with that of native lysozyme. The IPSF activity of lysozyme heat-treated at 83 degrees C in 4 M urea solution was enhanced 8.4-fold than that of native lysozyme. However, lysozyme that was not heated in 4 M urea solution completely lost its IPSF activity. This means that the IPSF activity of this enzyme in 4 M urea was reactivated by thermal treatment. Moreover, coexistence of 0.5 mM 2-mercaptoethanol (2-ME) during heating in 4 M urea solution extremely enhanced the IPSF activity up to 77.8-fold. The uptake of lysozyme by hybridoma cells was enhanced by heat denaturation in 4 M urea. The hydrophobicity of lysozyme was extremely increased by heat-treatment in 2-ME containing urea solution. It is expected from these findings that the increase in the hydrophobicity caused the enhancement of incorporation of lysozyme into target cells, and resulted in the acceleration of IgM production.
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Affiliation(s)
- Takuya Sugahara
- Department of Biotechnology, Faculty of Agriculture, Ehime University, Matsuyama, Japan.
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30
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Bhattacharjee C, Das KP. Thermal unfolding and refolding of beta-lactoglobulin. An intrinsic andextrinsic fluorescence study. EUROPEAN JOURNAL OF BIOCHEMISTRY 2000; 267:3957-64. [PMID: 10866794 DOI: 10.1046/j.1432-1327.2000.01409.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The conformational features of beta-lactoglobulin, refolded by cooling from a thermally perturbed state, has been characterized by intrinsic and extrinsic fluorescence measurements on the protein. It is found that even at 85-90 degrees C, beta-lactoglobulin does not completely lose its folded structure. The unfolding and refolding of beta-lactoglobulin as observed through intrinsic tryptophan fluorescence is nearly reversible because the native beta-lactoglobulin and its refolded form, following heating and cooling, show nearly identical tryptophan fluorescence properties. However, the fluorescence properties of an extrinsic probe 1-anilino 8-naphthalene sulfonic acid (ANS) for the native and refolded forms are quite different from each other. Significant increase in fluorescence intensity and blue shifts in emission maxima of ANS bound to refolded beta-lactoglobulin is observed compared to that of the native form. Our results indicate that beta-lactoglobulin, refolded after heating to above 70 degrees C, has deep hydrophobic pockets which can be accessed by ANS. These pockets are either nonexistent or inaccessible to ANS in native beta-lactoglobulin. The opening of the central cavity collapses at pH close to the isoelectric pH of the protein. This indicates that electrostatic repulsion is necessary to keep this access open.
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Affiliation(s)
- C Bhattacharjee
- Protein Chemistry Laboratory, Department of Chemistry, Bose Institute, Calcutta, India
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31
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Sudharshan E, Rao AG. Rapid method to separate the domains of soybean lipoxygenase-1: identification of the interdomain interactions. FEBS Lett 1997; 406:184-8. [PMID: 9109414 DOI: 10.1016/s0014-5793(97)00268-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Lipoxygenase-1 (LOX1) from soybeans was cleaved with chymotrypsin (Ramachandran et al., 31 (1992) 7700-7706). The domains were separated on a Sephadex G-50 column by minimising domain interactions at pH 4.0. The molecular weight and apparent homogeneity of the domains were established by SDS-PAGE. The solution conformation of the 60 kDa and 30 kDa fragments was compared with that of native LOX1. 1-Anilino-8-naphthalene sulphonate (ANS) binding measurements confirmed the exposure of large hydrophobic residues on the surface of the 60 kDa due to separation of the domains. The monomeric nature of the 60 kDa fragment was confirmed by HPLC gel filtration. The increased number of binding sites and magnitude of binding constant suggested the involvement of extensive hydrophobic interactions between the two domains. The essential cofactor iron was with the C-terminal domain. The attempts to resolve and reconstitute the catalytic activity of isolated domains were not successful.
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Affiliation(s)
- E Sudharshan
- Department of Protein Chemistry and Technology, Central Food Technological Research Institute, Mysore, India
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32
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APENTEN RICHARDKOWUSU, FOLAWIYO YETUNDEL. THE EFFECT OF pH ON RAPESEED GLOBULIN (CRUCIFERIN) BINDING TO ANILINONAPHTHALENE-8-SULFONATE. J Food Biochem 1995. [DOI: 10.1111/j.1745-4514.1995.tb00548.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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33
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Halder UC, Saha S, Sinha NK, Das KP. SURFACE PROPERTIES OF SOME LOW MOLECULAR WEIGHT PROTEINS. J DISPER SCI TECHNOL 1994. [DOI: 10.1080/01932699408943583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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