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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; 37:e3086. [PMID: 38686702 DOI: 10.1002/jmr.3086] [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: 11/26/2023] [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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2
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Grostete M, Lee J, Msibi Z, Boissel F, Jimenez M, Jeantet R, Lanotte L. Exploring the formation of surficial whey protein deposits under shear stress by rheofluidic approach. Int J Biol Macromol 2024; 274:133291. [PMID: 38908625 DOI: 10.1016/j.ijbiomac.2024.133291] [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: 04/16/2024] [Revised: 06/18/2024] [Accepted: 06/19/2024] [Indexed: 06/24/2024]
Abstract
Understanding how shear affects whey protein stability is crucial to deal with typical industrial issues occurring at the bulk solution/surface interface, such as fouling during heat treatments. However, at the state of the art, this effect remains unclear, contrary to that of temperature. This article presents a novel strategy to study the impact of shear rate and concentration on the accumulation of whey protein surficial deposits. It consists in applying a range of shear rates (0-200 s-1) at controlled temperature (65 °C) on whey protein solutions (5-10 wt%) by a parallel plate rheometer equipped with a glass disc, thus allowing the off-line characterization of the deposits by microscopy. Our results highlight an unequivocal effect of increasing shear stress. At 5 wt%, it fosters the formation of primary deposits (≈ 10 μm), whereas at 10 wt% it results in the development of complex branched structures (≈ 50 μm) especially for shear rates ranging from 140 s-1 to 200 s-1. Based on the classification by size of the observed populations, we discuss possible hypotheses for the deposit growth kinetics, involving the interplay of different physico-chemical protein-surface interactions and paving the way to future further investigations.
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Affiliation(s)
| | - Jeehyun Lee
- INRAE, Institut Agro, STLO, 35042 Rennes, France.
| | - Zanele Msibi
- INRAE, Institut Agro, STLO, 35042 Rennes, France.
| | | | - Maude Jimenez
- Univ. Lille, CNRS, INRAE, Centrale Lille, UMR 8207 - UMET - Unité Matériaux et Transformations, F-59000 Lille, France; Institut Universitaire de, France, (IUF), 1 rue Descartes, 75231 Paris cedex.
| | | | - Luca Lanotte
- INRAE, Institut Agro, STLO, 35042 Rennes, France.
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3
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Domínguez-López LG, Mejía-Manzano LA, González-Valdez J. Using the reactive/transport dispersive models to simulate a monolithic anion exchanger: Experimental parameter determination, simultaneous model evaluation, and validation. Electrophoresis 2024. [PMID: 38850174 DOI: 10.1002/elps.202300133] [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: 06/14/2023] [Revised: 11/21/2023] [Accepted: 04/30/2024] [Indexed: 06/10/2024]
Abstract
Selecting an adequate model to represent the mass transfer mechanisms occurring in a chromatographic process is generally complicated, which is one of the reasons why monolithic chromatography is scarcely simulated. In this study, the chromatographic separation of model proteins bovine serum albumin (BSA), β-lactoglobulin-A, and β-lactoglobulin-B on an anion exchange monolith was simulated based on experimental parameter determination, simultaneous model testing, and validation under three statistical criteria: retention time, dispersion accuracies, and Pearson correlation coefficient. Experimental characterization of morphologic, physicochemical, and kinetic parameters was performed through volume balances, pressure drop analysis, breakthrough curve analysis, and batch adsorptions. Free Gibbs energy indicated a spontaneous adsorption process for proteins and counterions. Dimensionless numbers were estimated based on height equivalent to a theoretical plate analysis, finding that pore diffusion controlled β-lactoglobulin separation, whereas adsorption/desorption kinetics was the dominant mechanism for BSA. The elution profiles were modeled using the transport dispersive model and the reactive dispersive model coupled with steric mass action (SMA) isotherms because these models allowed to consider most of the mass transport mechanisms that have been described. RDM-SMA presented the most accurate simulations at pH 6.0 and at low (250 mM) and high (400 mM) NaCl concentrations. This simulation will be used as reference to forecast the purification of these proteins from bovine whey waste and to extrapolate this methodology to other monolith-based separations using these three statistical criteria that have not been used previously for this purpose.
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Affiliation(s)
| | | | - José González-Valdez
- School of Engineering and Science, Tecnologico de Monterrey, Monterrey, Nuevo León, Mexico
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4
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Ghorbani F, Kim M, Ghalandari B, Zhang M, Varma SN, Schöbel L, Liu C, Boccaccini AR. Architecture of β-lactoglobulin coating modulates bioinspired alginate dialdehyde-gelatine/polydopamine scaffolds for subchondral bone regeneration. Acta Biomater 2024; 181:188-201. [PMID: 38642788 DOI: 10.1016/j.actbio.2024.04.028] [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: 01/22/2024] [Revised: 03/21/2024] [Accepted: 04/15/2024] [Indexed: 04/22/2024]
Abstract
In this study, we developed polydopamine (PDA)-functionalized alginate dialdehyde-gelatine (ADA-GEL) scaffolds for subchondral bone regeneration. These polymeric scaffolds were then coated with β-Lactoglobulin (β-LG) at concentrations of 1 mg/ml and 2 mg/ml. Morphological analysis indicated a homogeneous coating of the β-LG layer on the surface of network-like scaffolds. The β-LG-coated scaffolds exhibited improved swelling capacity as a function of the β-LG concentration. Compared to ADA-GEL/PDA scaffolds, the β-LG-coated scaffolds demonstrated delayed degradation and enhanced biomineralization. Here, a lower concentration of β-LG showed long-lasting stability and superior biomimetic hydroxyapatite mineralization. According to the theoretical findings, the single-state, representing the low concentration of β-LG, exhibited a homogeneous distribution on the surface of the PDA, while the dimer-state (high concentration) displayed a high likelihood of uncontrolled interactions. β-LG-coated ADA-GEL/PDA scaffolds with a lower concentration of β-LG provided a biocompatible substrate that supported adhesion, proliferation, and alkaline phosphatase (ALP) secretion of sheep bone marrow mesenchymal stem cells, as well as increased expression of osteopontin (SPP1) and collagen type 1 (COL1A1) in human osteoblasts. These findings indicate the potential of protein-coated scaffolds for subchondral bone tissue regeneration. STATEMENT OF SIGNIFICANCE: This study addresses a crucial aspect of osteochondral defect repair, emphasizing the pivotal role of subchondral bone regeneration. The development of polydopamine-functionalized alginate dialdehyde-gelatine (ADA-GEL) scaffolds, coated with β-Lactoglobulin (β-LG), represents a novel approach to potentially enhance subchondral bone repair. β-LG, a milk protein rich in essential amino acids and bioactive peptides, is investigated for its potential to promote subchondral bone regeneration. This research explores computationally and experimentally the influence of protein concentration on the ordered or irregular deposition, unravelling the interplay between coating structure, scaffold properties, and in-vitro performance. This work contributes to advancing ordered protein coating strategies for subchondral bone regeneration, providing a biocompatible solution with potential implications for supporting subsequent cartilage repair.
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Affiliation(s)
- Farnaz Ghorbani
- Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstrasse 6, 91058 Erlangen, Germany; Institute of Orthopaedic & Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital, Stanmore HA7 4LP, United Kingdom; Department of Translational Health Science, Bristol Medical School, University of Bristol, Bristol BS1 3NY, United Kingdom.
| | - Minjoo Kim
- Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstrasse 6, 91058 Erlangen, Germany; Department of Orthopaedics and Trauma Surgery, Musculoskeletal University Center Munich (MUM), LMU University Hospital, LMU Munich, 81377 Munich, Germany
| | - Behafarid Ghalandari
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Mingjing Zhang
- Institute of Orthopaedic & Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital, Stanmore HA7 4LP, United Kingdom
| | - Swastina Nath Varma
- Institute of Orthopaedic & Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital, Stanmore HA7 4LP, United Kingdom
| | - Lisa Schöbel
- Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstrasse 6, 91058 Erlangen, Germany
| | - Chaozong Liu
- Institute of Orthopaedic & Musculoskeletal Science, University College London, Royal National Orthopaedic Hospital, Stanmore HA7 4LP, United Kingdom.
| | - Aldo R Boccaccini
- Institute of Biomaterials, Department of Materials Science and Engineering, University of Erlangen-Nuremberg, Cauerstrasse 6, 91058 Erlangen, Germany.
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Yamazaki S, Takahashi K, Matsuda Y. Tag-free protein modification by lipoate ligase A: exploring substrate tolerance. ANAL SCI 2024; 40:1111-1119. [PMID: 38504072 DOI: 10.1007/s44211-024-00534-6] [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: 01/13/2024] [Accepted: 02/10/2024] [Indexed: 03/21/2024]
Abstract
This study delves into the functional intricacies of lipoate ligase A (LplA), an enzyme showing great promise in bioconjugation due to its unique capacity for introducing azido groups into proteins without requiring a genetic tag. We aimed to enhance the understanding of LplA's functionality, particularly its substrate tolerance and the reliability of various analytical techniques. A pivotal aspect of our approach was incorporating azido groups into a range of proteins, followed by the addition of the fluorescent molecule Cy3 via click chemistry. Analysis of fluorescent intensity in the altered proteins indicated varying degrees of conjugation. Additionally, phenyl resin-based RP-HPLC facilitated effective separation of modified proteins, unmodified proteins, and remaining fluorescent tags post-separation. SASA analysis provided insights into conjugation trends, guiding the identification of proteins amenable to LplA's tag-free modification. Our findings demonstrate LplA's broad substrate tolerability for protein modification.
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Affiliation(s)
- Shunsuke Yamazaki
- Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki, Kanagawa, 210-8681, Japan.
| | | | - Yutaka Matsuda
- Ajinomoto Co., Inc., 1-1 Suzuki-cho, Kawasaki, Kanagawa, 210-8681, Japan.
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Heiden-Hecht T, Wu B, Schwärzer K, Förster S, Kohlbrecher J, Holderer O, Frielinghaus H. New insights into protein stabilized emulsions captured via neutron and X-ray scattering: An approach with β-lactoglobulin at triacylglyceride-oil/water interfaces. J Colloid Interface Sci 2024; 655:319-326. [PMID: 37948805 DOI: 10.1016/j.jcis.2023.10.155] [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: 05/11/2023] [Revised: 10/25/2023] [Accepted: 10/29/2023] [Indexed: 11/12/2023]
Abstract
HYPOTHESIS To analyze protein stabilized emulsions, SAXS and SANS are emerging techniques capturing oil droplet radius, interfacial coverage and structure. Protein shape, thus protein structure change during interfacial adsorption with partial protein unfolding is detected via SAXS analysis at and below the monolayer concentration for proteins, known as critical interfacial concentration (CIC). SANS determines the same phenomena below and above the CIC, via contrast variation and coarse-grained modelling. EXPERIMENTS β-lactoglobulin concentration dependent SAXS experiments were performed focusing on molecular length scales to characterize protein shape in water, and interfacial structure in emulsions. Complementary SANS experiments with contrast variation via deuterated triacylglyceride-oil provided insight into oil droplet radius, interfacial coverage and structure via data analysis with scattering models and low-resolution shape reconstruction with the DENFERT model. FINDINGS SAXS and SANS experiments allowed to determine the interfacial structure below and above the CIC, as well as oil droplet radius and interfacial coverage. These findings were identified via Q-4 Porod scattering at low-Q, protein scattering at high Q, and a Q-2 scattering of the interface. Since SANS with accurate contrast variation highlights the interface in comparison to other techniques like FTIR, the presented results show a high impact to understand interfaces in emulsions.
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Affiliation(s)
- Theresia Heiden-Hecht
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany.
| | - Baohu Wu
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany
| | - Kuno Schwärzer
- Jülich Centre for Neutron Science (JCNS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | - Stephan Förster
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany; Jülich Centre for Neutron Science (JCNS-1), Forschungszentrum Jülich GmbH, 52425 Jülich, Germany
| | | | - Olaf Holderer
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany
| | - Henrich Frielinghaus
- Jülich Centre for Neutron Science (JCNS) at Heinz Maier-Leibnitz Zentrum (MLZ), Forschungszentrum Jülich GmbH, Lichtenbergstr. 1, 85747 Garching, Germany
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7
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Tammara V, Angrover R, Sirur D, Das A. Flagellar motor protein-targeted search for the druggable site of Helicobacter pylori. Phys Chem Chem Phys 2024; 26:2111-2126. [PMID: 38131449 DOI: 10.1039/d3cp05024f] [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: 12/23/2023]
Abstract
The deleterious impact of Helicobacter pylori (H. pylori) on human health is contingent upon its ability to create and sustain colony structure, which in turn is dictated by the effective performance of flagella - a multi-protein rotary nanodevice. Hence, to design an effective therapeutic strategy against H. pylori, we here conducted a systematic search for an effective druggable site by focusing on the structure-dynamics-energetics-stability landscape of the junction points of three 1 : 1 protein complexes (FliFC-FliGN, FliGM-FliMM, and FliYC-FliNC) that contribute mainly to the rotary motion of the flagella via the transformation of information along the junctions over a wide range of pH values operative in the stomach (from neutral to acidic). We applied a gamut of physiologically relevant perturbations in the form of thermal scanning and mechanical force to sample the entire quasi - and non-equilibrium conformational spaces available for the protein complexes under neutral and acidic pH conditions. Our perturbation-induced magnification of conformational distortion approach identified pH-independent protein sequence-specific evolution of precise thermally labile segments, which dictate the specific thermal unfolding mechanism of each complex and this complex-specific pH-independent structural disruption notion remains consistent under mechanical stress as well. Complementing the above observations with the relative rank-ordering of estimated equilibrium binding free energies between two protein sequences of a specific complex quantifies the extent of structure-stability modulation due to pH alteration, rationalizes the exceptional stability of H. pylori under acidic pH conditions, and identifies the pH-independent complex-sequence-segment-residue diagram for targeted drug design.
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Affiliation(s)
- Vaishnavi Tammara
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pune, Maharashtra 411008, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
| | - Ruchika Angrover
- The Departments of the University Institute of Biotechnology, Chandigarh University, NH-05, Ludhiana - Chandigarh State Highway, Punjab 140413, India
| | - Disha Sirur
- School of Physical Sciences, National Institute of Science Education & Research-Bhubaneswar, An OCC of Homi Bhabha National Institute, P.O. Jatni, Khurda, Odisha 752050, India
| | - Atanu Das
- Physical and Materials Chemistry Division, CSIR-National Chemical Laboratory, Dr Homi Bhabha Road, Pune, Maharashtra 411008, India.
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India
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8
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Ghasemi M, Habibian-Dehkordi S, Farhadian S. Change in thermal stability and molecular structure characteristics of whey protein beta-lactoglobulin upon the interaction with levamisole hydrochloride. Food Chem 2024; 431:137073. [PMID: 37598650 DOI: 10.1016/j.foodchem.2023.137073] [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: 02/23/2023] [Revised: 07/26/2023] [Accepted: 07/31/2023] [Indexed: 08/22/2023]
Abstract
The interaction between beta-lactoglobulin (BLG) and anthelmintic compounds including levamisole (LEV) is a matter of great concern as it not only poses potential health and environmental risks but also has significant implications for food processing and production. The mechanisms of LEV-BLG interaction were investigated through spectral and molecular modeling approaches. Fluorescence and UV-Visible investigations indicated the formation of a spontaneous and stable LEV-BLG complex. Structural changes of BLG were revealed by circular dichroism and Fourier transform infrared studies. The thermal stability of BLG increased in the presence of LEV. Molecular docking studies indicated the best mode of LEV-BLG interaction and molecular dynamics simulation confirmed the stability of the LEV-BLG complex. In conclusion, our study sheds light on the potential of BLG to interact with deleterious substances such as anthelmintic agents, thus highlighting the necessity of further research in this field to assure food safety and prevent any health hazards.
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Affiliation(s)
- Mohammad Ghasemi
- Department of Pharmacology, School of Veterinary Medicine, Shahrekord University, P. O. Box 115, Shahrekord, Iran
| | - Saied Habibian-Dehkordi
- Department of Pharmacology, School of Veterinary Medicine, Shahrekord University, P. O. Box 115, Shahrekord, Iran.
| | - Sadegh Farhadian
- Department of Biology, Faculty of Science, Shahrekord University, Shahrekord, P. O. Box 115, Iran; Central Laboratory, Shahrekord University, Shahrekord, Iran.
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9
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Paul B, Furst EM, Lenhoff AM, Wagner NJ, Teixeira SCM. Combined Effects of Pressure and Ionic Strength on Protein-Protein Interactions: An Empirical Approach. Biomacromolecules 2024; 25:338-348. [PMID: 38117685 DOI: 10.1021/acs.biomac.3c01001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2023]
Abstract
Proteins are exposed to hydrostatic pressure (HP) in a variety of ecosystems as well as in processing steps such as freeze-thaw, cell disruption, sterilization, and homogenization, yet pressure effects on protein-protein interactions (PPIs) remain underexplored. With the goal of contributing toward the expanded use of HP as a fundamental control parameter in protein research, processing, and engineering, small-angle X-ray scattering was used to examine the effects of HP and ionic strength on ovalbumin, a model protein. Based on an extensive data set, we develop an empirical method for scaling PPIs to a master curve by combining HP and osmotic effects. We define an effective pressure parameter that has been shown to successfully apply to other model protein data available in the literature, with deviations evident for proteins that do not follow the apparent Hofmeister series. The limitations of the empirical scaling are discussed in the context of the hypothesized underlying mechanisms.
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Affiliation(s)
- Brian Paul
- Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
| | - Eric M Furst
- Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Abraham M Lenhoff
- Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Norman J Wagner
- Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
| | - Susana C M Teixeira
- Center for Neutron Science, Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, Delaware 19716, United States
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
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10
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Liu Y, He B, Liu L, Hu L, Jiang G. Fasten the analysis of metal-binding proteins with GE-ICP-MS via increasing the electrolyte concentration of the running buffer. Talanta 2024; 266:125047. [PMID: 37574606 DOI: 10.1016/j.talanta.2023.125047] [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: 03/26/2023] [Revised: 07/19/2023] [Accepted: 08/05/2023] [Indexed: 08/15/2023]
Abstract
The coupled system of column gel electrophoresis and inductively coupled plasma mass spectrometry (GE-ICP-MS) is a highly effective technique for detecting metal-binding proteins. However, it takes a long time for this method to test a single sample, which greatly limits its application. In this study, GE-ICP-MS system was optimized by adjusting the analytical conditions, including the concentration and pH of running buffer and the proportion of polyacrylamide gel. The results of the experiment showed that the migration speed of proteins in GE was enhanced by increasing the electrolyte concentration in the running buffer solution. Additionally, the ICP-MS response, which was dramatically decreased because of the change in running buffer solution, can be stabilized by adjusting pH of running buffer. Meanwhile, the optimization of polyacrylamide gel ratio allows GE-ICP-MS to maintain high resolution for proteins of similar molecular weight with increased detection speed. After increasing the concentration of running buffer by 10 times, four iodine labeled proteins were successfully separated at baseline by the GE-ICP-MS system at pH 8.0 in 40 min using a resolving gel (8%, 7 cm) and a stacking gel (4%, 1 cm), which was three times faster than the original one. Finally, the optimized method was proved by detecting a silver-binding protein in rat plasma samples. The above method provided an effective and rapid detection for metal-binding proteins in organism.
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Affiliation(s)
- Yingqiu Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Bin He
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310000, China.
| | - Lihong Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Ligang Hu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China; School of Environment, Hangzhou Institute for Advanced Study, University of Chinese Academy of Sciences, Hangzhou, 310000, China; School of Environment and Health, Jianghan University, Wuhan, 430056, China; College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Guibin Jiang
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing, 100085, China
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11
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Li S, Murakami D, Nagatoishi S, Liu Y, Tsumoto K, Katayama Y, Mori T. One-pot preparation of mannan-coated antigen nanoparticles using human serum albumin as a matrix for tolerance induction. J Colloid Interface Sci 2023; 649:955-965. [PMID: 37392685 DOI: 10.1016/j.jcis.2023.06.170] [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: 03/24/2023] [Revised: 06/10/2023] [Accepted: 06/25/2023] [Indexed: 07/03/2023]
Abstract
Nanoparticles (NPs) for allergen immunotherapy have garnered attention for their high efficiency and safety compared with naked antigen proteins. In this work, we present mannan-coated protein NPs, incorporating antigen proteins for antigen-specific tolerance induction. The heat-induced formation of protein NPs is a one-pot preparation method and can be applied to various proteins. Here, the NPs were formed spontaneously via heat denaturation of three component proteins: an antigen protein, human serum albumin (HSA) as a matrix protein, and mannoprotein (MAN) as a targeting ligand for dendritic cells (DCs). HSA is non-immunogenic, therefore suitable as a matrix protein, while MAN coats the surface of the NP. We applied this method to various antigen proteins and found that the self-disperse after heat denaturation was a requirement for incorporation into the NPs. We also established that the NPs could target DCs, and the incorporation of rapamycin into the NPs enhanced the induction of a tolerogenic phenotype of DC. The MAN coating provided steric hindrance and heat denaturation destroyed recognition structures, successfully preventing anti-antigen antibody binding, indicating the NPs may avoid anaphylaxis induction. The MAN-coated NPs proposed here, prepared by a simple method, have the potential for effective and safe allergies treatment for various antigens.
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Affiliation(s)
- Shunyi Li
- Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan
| | - Daisuke Murakami
- Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, 812-8582 Fukuoka, Japan
| | - Satoru Nagatoishi
- The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Department of Bioengineering, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Yiwei Liu
- Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Fukuoka 819-0395, Japan
| | - Kouhei Tsumoto
- The Institute of Medical Science, The University of Tokyo, Tokyo 108-8639, Japan; Department of Bioengineering, School of Engineering, The University of Tokyo, Tokyo 113-8656, Japan
| | - Yoshiki Katayama
- Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan; Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Fukuoka 819-0395, Japan; Center for Future Chemistry, Kyushu University, 819-0395, Japan; International Research Center for Molecular Systems, Kyushu University, Fukuoka 819-0395, Japan; Centre for Advanced Medicine Innovation, Kyushu University, Fukuoka 812-8582, Japan; Department of Biomedical Engineering, Chung Yuan Christian University, Chung Li, 32023, Taiwan, ROC.
| | - Takeshi Mori
- Graduate School of Systems Life Sciences, Kyushu University, Fukuoka 819-0395, Japan; Department of Applied Chemistry, Faculty of Engineering, Kyushu University, Fukuoka 819-0395, Japan; Center for Future Chemistry, Kyushu University, 819-0395, Japan.
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12
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Ostertag F, Hinrichs J. Enrichment of Lactoferrin and Immunoglobulin G from Acid Whey by Cross-Flow Filtration. Foods 2023; 12:foods12112163. [PMID: 37297408 DOI: 10.3390/foods12112163] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 05/21/2023] [Accepted: 05/23/2023] [Indexed: 06/12/2023] Open
Abstract
The production of cream cheese, curd, high-protein yogurt, or caseinate results in large amounts of acid whey as a by-product. So far acid whey is often disposed as animal feed or organic fertilizer. However, these approaches ignore the valorization potential that arises from the unique composition of the whey protein fraction. Whey contains the biofunctional proteins lactoferrin and immunoglobulin G, which possess immune-supporting, antibacterial, antiviral, and numerous further health-promoting functions. However, the concentration of these proteins in bovine milk or whey is below a physiologically relevant level. Based on literature research we specified a daily intake of 200 mg lactoferrin as the minimal functional dose. By means of cross-flow ultrafiltration, an attempt was made to increase the concentration of biofunctional proteins. Therefore, a membrane for the selective retention of lactoferrin and immunoglobulin G was identified, and the process parameters were optimized. Finally, a concentration experiment was conducted, whereby the concentration of biofunctional proteins was increased up to factor 30. The biofunctionality was assessed in a microbiological assay. Surprisingly, the antimicrobial growth inhibition of the produced concentrate was even higher than in pure lactoferrin. The presented approach offers a strategy to convert an abundant but underutilized by-product into valuable products for human nutrition.
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Affiliation(s)
- Fabian Ostertag
- Department of Soft Matter Science and Dairy Technology, Institute of Food Science and Biotechnology, University of Hohenheim, Garben Str. 21, 70599 Stuttgart, Germany
| | - Jörg Hinrichs
- Department of Soft Matter Science and Dairy Technology, Institute of Food Science and Biotechnology, University of Hohenheim, Garben Str. 21, 70599 Stuttgart, Germany
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13
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Han Q, El Mohamad M, Brown S, Zhai J, Rosado CJ, Shen Y, Blanch EW, Drummond CJ, Greaves TL. Small angle X-ray scattering investigation of ionic liquid effect on the aggregation behavior of globular proteins. J Colloid Interface Sci 2023; 648:376-388. [PMID: 37302221 DOI: 10.1016/j.jcis.2023.05.130] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 05/02/2023] [Accepted: 05/18/2023] [Indexed: 06/13/2023]
Abstract
Globular proteins are well-folded model proteins, where ions can substantially influence their structure and aggregation. Ionic liquids (ILs) are salts in the liquid state with versatile ion combinations. Understanding the IL effect on protein behavior remains a major challenge. Here, we employed small angle X-ray scattering to investigate the effect of aqueous ILs on the structure and aggregation of globular proteins, namely, hen egg white lysozyme (Lys), human lysozyme (HLys), myoglobin (Mb), β-lactoglobulin (βLg), trypsin (Tryp) and superfolder green fluorescent protein (sfGFP). The ILs contain ammonium-based cations paired with the mesylate, acetate or nitrate anion. Results showed that only Lys was monomeric, whereas the other proteins formed small or large aggregates in buffer. Solutions with over 17 mol% IL resulted in significant changes in the protein structure and aggregation. The Lys structure was expanded at 1 mol% but compact at 17 mol% with structural changes in loop regions. HLys formed small aggregates, with the IL effect similar to Lys. Mb and βLg mostly had distinct monomer and dimer distributions depending on IL type and IL concentration. Complex aggregation was noted for Tryp and sfGFP. While the anion had the largest ion effect, changing the cation also induced the structural expansion and protein aggregation.
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Affiliation(s)
- Qi Han
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia.
| | - Mohamad El Mohamad
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Stuart Brown
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Jiali Zhai
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Carlos J Rosado
- Department of Diabetes, Central Clinical School, Monash University, VIC 3004, Australia; Department of Biochemistry, Monash University, VIC 3800, Australia
| | - Yi Shen
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia; The University of Sydney Nano Institute, The University of Sydney, Sydney, NSW 2006, Australia
| | - Ewan W Blanch
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Calum J Drummond
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia
| | - Tamar L Greaves
- School of Science, STEM College, RMIT University, Melbourne, VIC 3000, Australia.
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14
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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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15
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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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16
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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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17
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Hossain M, Huda N, Bhuyan AK. A surprisingly simple three-state generic process for reversible protein denaturation by trifluoroethanol. Biophys Chem 2022; 291:106895. [PMID: 36182744 DOI: 10.1016/j.bpc.2022.106895] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 09/12/2022] [Accepted: 09/14/2022] [Indexed: 12/30/2022]
Abstract
Despite the rich knowledge of the influence of 2,2,2-trifluoroethanol (TFE) on the structure and conformation of peptides and proteins, the mode(s) of TFE-protein interactions and the mechanism by which TFE reversibly denatures a globular protein remain elusive. This study systematically examines TFE-induced equilibrium transition curves for six paradigmatic globular proteins by using basic fluorescence and circular dichroism measurements under neutral pH conditions. The results are remarkably simple. Low TFE invariably unfolds the tertiary structure of all proteins to produce the obligate intermediate (I) which retains nearly all of native-state secondary structure, but enables the formation of extra α-helices as the level of TFE is raised higher. Inspection of the transitions at once reveals that the tertiary structure unfolding is always a distinct process, necessitating the inclusion of at least one obligate intermediate in the TFE-induced protein denaturation. It appears that the intermediate in the minimal unfolding mechanism N⇌I⇌D somehow acquires higher α-helical propensity to generate α-helices in excess of that in the native state to produce the denatured state (D), also called the TFE state. The low TFE-populated intermediate I may be called a universal intermediate by virtue of its α-helical propensity. Contrary to many earlier suggestions, this study dismisses molten globule (MG)-like attribute of I or D.
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Affiliation(s)
- Mujahid Hossain
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Noorul Huda
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India
| | - Abani K Bhuyan
- School of Chemistry, University of Hyderabad, Hyderabad 500046, India.
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18
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Habibian-Dehkordi S, Farhadian S, Ghasemi M, Evini M. Insight into the binding behavior, structure, and thermal stability properties of β-lactoglobulin/Amoxicillin complex in a neutral environment. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107830] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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19
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Mohammad-Beigi H, Wijaya W, Madsen M, Hayashi Y, Li R, Maria Rovers TA, Jæger TC, Buell AK, Hougaard AB, Kirkensgaard JJ, Westh P, Ipsen R, Svensson B. Association of caseins with β-lactoglobulin influenced by temperature and calcium ions: A multi-parameter analysis. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.108373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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20
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Lu Y, Zhao R, Wang C, Zhang X, Wang C. Deciphering the non-covalent binding patterns of three whey proteins with rosmarinic acid by multi-spectroscopic, molecular docking and molecular dynamics simulation approaches. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107895] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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21
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Luo Z, Wang Z. The role of starch granule-associated proteins in enhancing the strength of indica rice starch gels. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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22
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Uttinger MJ, Hundschell CS, Lautenbach V, Pusara S, Bäther S, Heyn TR, Keppler JK, Wenzel W, Walter J, Kozlowska M, Wagemans AM, Peukert W. Determination of specific and non-specific protein-protein interactions for beta-lactoglobulin by analytical ultracentrifugation and membrane osmometry experiments. SOFT MATTER 2022; 18:6739-6756. [PMID: 36040122 DOI: 10.1039/d2sm00908k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Protein-protein interactions are essential for the understanding of biological processes. Specific protein aggregation is an important aspect for many biological systems. In particular, electrostatic interactions play the key role for protein-protein interactions, as many amino acids have pH-dependent charge states. Moreover, protein dissociation is directly related to the solution pH, ionic strength, temperature and protein concentration. The subtle interplay between different specific and non-specific interactions is demonstrated for beta-lactoglobulin (BLG) with a focus on low salt concentrations, thus mimicking technically relevant processing conditions. BLG is a well-characterized model system, proven to attain its monomer-dimer equilibrium strongly dependent upon the pH of the solution. In this manuscript, we present a unique combination of analytical ultracentrifugation and membrane osmometry experiments, which quantifies specific and non-specific interactions, i.e. in terms of the dimer dissociation constants and the second osmotic virial coefficient, at pH 3 and 7 and sodium chloride concentrations of 10 mM and 100 mM. This provides direct insight to protein-protein interactions for a system with a concentration-dependent monomer-dimer equilibrium. Moreover, using a coarse-grained extended DLVO model in combination with molecular dynamics simulations, we quantify non-specific monomer-monomer, monomer-dimer and dimer-dimer interactions as well as the binding free energy of BLG dimerization from theoretical calculations. The experimentally determined interactions are shown to be mainly governed by electrostatic interactions and further agree with free energy calculations. Our experimental protocol aims to determine non-specific and specific interactions for a dynamically interacting system and provides an understanding of protein-protein interactions for BLG at low salt concentrations.
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Affiliation(s)
- M J Uttinger
- Institute of Particle Technology, Interdisciplinary Center for Functional Particle Systems, Friedrich-Alexander-Universität Erlangen-Nürnberg, Haberstraße 9a, 91058 Erlangen, Germany.
| | - C S Hundschell
- Institute of Food Technology and Food Chemistry, Department of Food Colloids, Technical University Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - V Lautenbach
- Institute of Particle Technology, Interdisciplinary Center for Functional Particle Systems, Friedrich-Alexander-Universität Erlangen-Nürnberg, Haberstraße 9a, 91058 Erlangen, Germany.
| | - S Pusara
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - S Bäther
- Institute of Food Technology and Food Chemistry, Department of Food Colloids, Technical University Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - T R Heyn
- Institute of Human Nutrition and Food Science, Division of Food Technology, Kiel University, 24118 Kiel, Germany
| | - J K Keppler
- Laboratory of Food Process Engineering, Wageningen University, Wageningen, The Netherlands
| | - W Wenzel
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - J Walter
- Institute of Particle Technology, Interdisciplinary Center for Functional Particle Systems, Friedrich-Alexander-Universität Erlangen-Nürnberg, Haberstraße 9a, 91058 Erlangen, Germany.
| | - M Kozlowska
- Institute of Nanotechnology, Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
| | - A M Wagemans
- Institute of Food Technology and Food Chemistry, Department of Food Colloids, Technical University Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany
| | - W Peukert
- Institute of Particle Technology, Interdisciplinary Center for Functional Particle Systems, Friedrich-Alexander-Universität Erlangen-Nürnberg, Haberstraße 9a, 91058 Erlangen, Germany.
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23
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Majid N, Siddiqi MK, Alam A, Malik S, Ali W, Khan RH. Cholic acid inhibits amyloid fibrillation: Interplay of protonation and deprotonation. Int J Biol Macromol 2022; 221:900-912. [PMID: 36096254 DOI: 10.1016/j.ijbiomac.2022.09.019] [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: 07/04/2022] [Revised: 08/23/2022] [Accepted: 09/04/2022] [Indexed: 11/29/2022]
Abstract
Amyloidopathies are the consequence of misfolding with subsequent aggregation affecting people worldwide. Irrespective of speedy advancement in the field of therapeutics no agent for treating amyloidopathies has been discovered and thus targeting amyloid fibrillation process via repositioning of small molecules can be fruitful. According to previous reports potential amyloid inhibitors possess unique features like, hydrophobicity, aromaticity, charge etc. Herein, we have explored the effect of Cholic acid (CA) on amyloid fibrillation irrespective of the charge (determined by Zetasizer) using four proteins Human Serum Albumin, Bovine Serum Albumin, Human Insulin and Beta-lactoglobulin (HSA, BSA, HI and BLG) employing biophysical, imaging and computational techniques. ThT results revealed that CA in both protonated and deprotonated form is potent to curb HSA, BSA, BLG aggregation ~50% and HI aggregation ~96% in a dose dependent manner (in accord with CD, ANS and Congo red assay). Interestingly, CA treated samples displayed reduced cytotoxicity (Hemolytic assay) with altered morphology (TEM) and mechanism behind inhibition may be the interaction of CA with proteins via hydrophobic interactions and hydrogen bonding (supported by molecular docking results). This study proved CA (irrespective of the pH) a potential inhibitor of amyloidosis thus can be helpful in generalizing and repurposing the related drugs/compounds for their anti-aggregation behavior as an implication towards treating amyloidopathies.
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Affiliation(s)
- Nabeela Majid
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | | | - Aftab Alam
- Centre for Interdisciplinary Research in Basic Science, Jamia Millia Islamia, New Delhi 110025, India
| | - Sadia Malik
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Wareesha Ali
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India
| | - Rizwan Hasan Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202002, India.
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24
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Jensen SA, Fiocchi A, Baars T, Jordakieva G, Nowak-Wegrzyn A, Pali-Schöll I, Passanisi S, Pranger CL, Roth-Walter F, Takkinen K, Assa'ad AH, Venter C, Jensen-Jarolim E. Diagnosis and Rationale for Action against Cow's Milk Allergy (DRACMA) Guidelines update - III - Cow's milk allergens and mechanisms triggering immune activation. World Allergy Organ J 2022; 15:100668. [PMID: 36185551 PMCID: PMC9483786 DOI: 10.1016/j.waojou.2022.100668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 06/17/2022] [Accepted: 06/19/2022] [Indexed: 11/30/2022] Open
Abstract
Background The immunopathogenesis of cow's milk protein allergy (CMPA) is based on different mechanisms related to immune recognition of protein epitopes, which are affected by industrial processing. Purpose The purpose of this WAO DRACMA paper is to: (i) give a comprehensive overview of milk protein allergens, (ii) to review their immunogenicity and allergenicity in the context of industrial processing, and (iii) to review the milk-related immune mechanisms triggering IgE-mediated immediate type hypersensitivity reactions, mixed reactions and non-IgE mediated hypersensitivities. Results The main cow’s milk allergens – α-lactalbumin, β-lactoglobulin, serum albumin, caseins, bovine serum albumins, and others – may determine allergic reactions through a range of mechanisms. All marketed milk and milk products have undergone industrial processing that involves heating, filtration, and defatting. Milk processing results in structural changes of immunomodulatory proteins, leads to a loss of lipophilic compounds in the matrix, and hence to a higher allergenicity of industrially processed milk products. Thereby, the tolerogenic capacity of raw farm milk, associated with the whey proteins α-lactalbumin and β-lactoglobulin and their lipophilic ligands, is lost. Conclusion The spectrum of immunopathogenic mechanisms underlying cow's milk allergy (CMA) is wide. Unprocessed, fresh cow's milk, like human breast milk, contains various tolerogenic factors that are impaired by industrial processing. Further studies focusing on the immunological consequences of milk processing are warranted to understand on a molecular basis to what extent processing procedures make single milk compounds into allergens.
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Affiliation(s)
- Sebastian A Jensen
- Institute of Pathophysiology and Allergy Research, Centre of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.,University Clinics for Ear Nose and Throat, Medical University Vienna, Austria.,The Interuniversity Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University Vienna and University Vienna, Vienna, Austria
| | - Alessandro Fiocchi
- Allergy Unit - Area of Translational Research in Pediatric Specialities, Bambino Gesù Children's Hospital, Rome, Italy
| | - Ton Baars
- Division of Pharmacology, Department of Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - Galateja Jordakieva
- Department of Physical Medicine, Rehabilitation and Occupational Medicine, Medical University of Vienna, Austria
| | - Anna Nowak-Wegrzyn
- Department of Pediatrics, NYU Grossman School of Medicine, Hassenfeld Childrens' Hospital, New York, NY, USA.,Department of Pediatrics, Gastroenterology and Nutrition, Collegium Medicum, University of Warmia and Mazury, Olsztyn, Poland
| | - Isabella Pali-Schöll
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.,AllergyCare - Allergy Diagnosis Center Vienna, Private Clinics Döbling, Vienna, Austria
| | - Stefano Passanisi
- Department of Human Pathology of Adult and Developmental Age, University of Messina, Italy
| | - Christina L Pranger
- Institute of Pathophysiology and Allergy Research, Centre of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.,The Interuniversity Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University Vienna and University Vienna, Vienna, Austria
| | - Franziska Roth-Walter
- University Clinics for Ear Nose and Throat, Medical University Vienna, Austria.,The Interuniversity Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University Vienna and University Vienna, Vienna, Austria
| | | | - Amal H Assa'ad
- Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Carina Venter
- Childrenás Hospital Colorado, University of Colorado, Denver, CO, USA
| | - Erika Jensen-Jarolim
- Institute of Pathophysiology and Allergy Research, Centre of Pathophysiology, Infectiology and Immunology, Medical University of Vienna, Vienna, Austria.,The Interuniversity Messerli Research Institute of the University of Veterinary Medicine Vienna, Medical University Vienna and University Vienna, Vienna, Austria.,AllergyCare - Allergy Diagnosis Center Vienna, Private Clinics Döbling, Vienna, Austria
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25
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Burova TV, Grinberg NV, Dubovik AS, Plashchina IG, Usov AI, Grinberg VY. β-Lactoglobulin–fucoidan nanocomplexes: Energetics of formation, stability, and oligomeric structure of the bound protein. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2022.107666] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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26
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Bui D, Li Z, Kitov PI, Han L, Kitova EN, Fortier M, Fuselier C, Granger Joly de Boissel P, Chatenet D, Doucet N, Tompkins SM, St-Pierre Y, Mahal LK, Klassen JS. Quantifying Biomolecular Interactions Using Slow Mixing Mode (SLOMO) Nanoflow ESI-MS. ACS CENTRAL SCIENCE 2022; 8:963-974. [PMID: 35912341 PMCID: PMC9335916 DOI: 10.1021/acscentsci.2c00215] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Electrospray ionization mass spectrometry (ESI-MS) is a powerful label-free assay for detecting noncovalent biomolecular complexes in vitro and is increasingly used to quantify binding thermochemistry. A common assumption made in ESI-MS affinity measurements is that the relative ion signals of free and bound species quantitatively reflect their relative concentrations in solution. However, this is valid only when the interacting species and their complexes have similar ESI-MS response factors (RFs). For many biomolecular complexes, such as protein-protein interactions, this condition is not satisfied. Existing strategies to correct for nonuniform RFs are generally incompatible with static nanoflow ESI (nanoESI) sources, which are typically used for biomolecular interaction studies, thereby significantly limiting the utility of ESI-MS. Here, we introduce slow mixing mode (SLOMO) nanoESI-MS, a direct technique that allows both the RF and affinity (K d) for a biomolecular interaction to be determined from a single measurement using static nanoESI. The approach relies on the continuous monitoring of interacting species and their complexes under nonhomogeneous solution conditions. Changes in ion signals of free and bound species as the system approaches or moves away from a steady-state condition allow the relative RFs of the free and bound species to be determined. Combining the relative RF and the relative abundances measured under equilibrium conditions enables the K d to be calculated. The reliability of SLOMO and its ease of use is demonstrated through affinity measurements performed on peptide-antibiotic, protease-protein inhibitor, and protein oligomerization systems. Finally, affinities measured for the binding of human and bacterial lectins to a nanobody, a viral glycoprotein, and glycolipids displayed within a model membrane highlight the tremendous power and versatility of SLOMO for accurately quantifying a wide range of biomolecular interactions important to human health and disease.
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Affiliation(s)
- Duong
T. Bui
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Zhixiong Li
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Pavel I. Kitov
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Ling Han
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Elena N. Kitova
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Marlène Fortier
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Camille Fuselier
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Philippine Granger Joly de Boissel
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - David Chatenet
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Nicolas Doucet
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Stephen M. Tompkins
- Center
for Vaccines and Immunology, University
of Georgia, Athens, Georgia 30605, United States
- Emory-UGA
Centers of Excellence for Influenza Research and Surveillance (CEIRS), Emory University School of Medicine, Athens, Georgia 30322, United States
| | - Yves St-Pierre
- Centre
Armand-Frappier Santé Biotechnologie, Institut National de la Recherche Scientifique (INRS), Université
du Québec, Laval, Québec H7V 1B7, Canada
| | - Lara K. Mahal
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - John S. Klassen
- Department
of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
- . Telephone: (780) 492-3501. Fax: (780) 492-8231
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27
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Minić S, Annighöfer B, Hélary A, Sago L, Cornu D, Brûlet A, Combet S. Structure of proteins under pressure: covalent binding effects of biliverdin on β-lactoglobulin. Biophys J 2022; 121:2514-2525. [DOI: 10.1016/j.bpj.2022.06.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Revised: 05/18/2022] [Accepted: 05/31/2022] [Indexed: 11/17/2022] Open
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28
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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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29
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Turck D, Bohn T, Castenmiller J, De Henauw S, Hirsch‐Ernst KI, Maciuk A, Mangelsdorf I, McArdle HJ, Naska A, Pelaez C, Pentieva K, Siani A, Thies F, Tsabouri S, Vinceti M, Cubadda F, Frenzel T, Heinonen M, Marchelli R, Neuhäuser‐Berthold M, Poulsen M, Prieto Maradona M, Schlatter JR, van Loveren H, Fernández Dumont A, Noriega Fernández E, Knutsen HK. Safety of Beta‐lactoglobulin as a Novel food pursuant to Regulation (EU) 2015/2283. EFSA J 2022; 20:e07204. [PMID: 35422882 PMCID: PMC8990528 DOI: 10.2903/j.efsa.2022.7204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Following a request from the European Commission, the EFSA Panel on Nutrition, Novel Foods and Food Allergens (NDA) was asked to deliver an opinion on beta‐lactoglobulin (BLG) as a novel food (NF) pursuant to Regulation (EU) 2015/2283. The NF (≥ 90% w/w dry matter protein) consists of BLG as primary component (≥ 90% of total protein), which is equivalent to BLG present in bovine milk and whey protein isolate (WPI). The NF is produced from bovine whey by crystallisation under acidic or neutral conditions. The NF is proposed to be used as a food ingredient in isotonic and sport drinks, whey powder and milk‐based drinks and similar products, and in food for special medical purposes as defined in Regulation (EU) No 609/2013. The target population is the general population. The highest daily intake of the NF was estimated for children of 3 to < 10 years of age as 667 mg/kg body weight (bw) per day. The NF presents proximate composition and content of essential amino acids similar to those in WPI. The Panel notes that the highest mean and highest 95th percentile daily protein intakes from the NF are below the protein population reference intakes for all population groups. Although a tolerable upper intake level has not been derived for protein, the protein intake from the NF may nevertheless further contribute to an already high dietary protein intake in Europe. The exposure to the reported minerals does not raise concerns. The Panel considers that the consumption of the NF is not nutritionally disadvantageous. No genotoxic concerns were identified from the standard in vitro test battery. No adverse effects were observed in the subchronic toxicity study, up to the highest dose tested, i.e. 1,000 mg NF/kg bw per day. The Panel concludes that the NF is safe under the proposed conditions of use.
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30
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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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31
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Khan JM, Malik A, Husain FM, Hakeem MJ, Alhomida AS. Sunset Yellow Dye Induces Amorphous Aggregation in β-Lactoglobulin at Acidic pH: A Multi-Techniques Approach. Polymers (Basel) 2022; 14:polym14030395. [PMID: 35160385 PMCID: PMC8839080 DOI: 10.3390/polym14030395] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 02/01/2023] Open
Abstract
Protein aggregation is of two types: (i) amorphous and (ii) amyloid fibril. Several extrinsic factors (temperature, pH, and small ligands) stimulate protein aggregation in vitro. In this study, we have examined the role of sunset yellow (SY) on the β-lactoglobulin (BLG) aggregation at pH 2.0. We have used spectroscopic (turbidity, Rayleigh light scattering (RLS), far-UV CD) and microscopic (transmission electron microscopy [TEM]) techniques to describe the effects of SY on BLG aggregation. Our results showed that BLG aggregation is dependent on SY concentrations. Very low concentrations (0.0–0.07 mM) of SY were unable to induce aggregation, while SY in the concentrations range of 0.1–5.0 mM induces aggregation in BLG. The kinetics of SY-stimulated aggregation is very fast and monomeric form of BLG directly converted into polymeric aggregates. The kinetics results also showed SY-induced BLG aggregation disappeared in the presence of NaCl. The far-UV CD and TEM results indicated the amorphous nature of SY-induced BLG aggregates. We believe that our results clearly suggest that SY dye effectively stimulates BLG aggregation.
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Affiliation(s)
- Javed Masood Khan
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia; (F.M.H.); (M.J.H.)
- Correspondence:
| | - Ajamaluddin Malik
- Department of Biochemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; (A.M.); (A.S.A.)
| | - Fohad Mabood Husain
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia; (F.M.H.); (M.J.H.)
| | - Mohammed J. Hakeem
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, Riyadh 11451, Saudi Arabia; (F.M.H.); (M.J.H.)
| | - Abdullah S. Alhomida
- Department of Biochemistry, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; (A.M.); (A.S.A.)
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32
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Burova TV, Grinberg NV, Dubovik AS, Plashchina IG, Usov AI, Grinberg VY. Energetics and mechanism of β-lactoglobulin binding to dextran sulfate. Food Hydrocoll 2022. [DOI: 10.1016/j.foodhyd.2021.107027] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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33
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Darmawan KK, Karagiannis TC, Hughes JG, Small DM, Hung A. Effects of low temperatures on the conformation of apo-lactoferrin and its interactions with α-lactalbumin and β-lactoglobulin: Application of in silico approaches. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2021.107055] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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34
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Zhang L, Zhou R, Zhang J, Zhou P. Heat-induced denaturation and bioactivity changes of whey proteins. Int Dairy J 2021. [DOI: 10.1016/j.idairyj.2021.105175] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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35
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Ramamirtham S, Whitby CP, Zare D, Weeks M, Williams MA. The rheological properties of bovine β-Lactoglobulin stabilized oil/water interfaces depend on the protein's quaternary structure. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2021.106834] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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36
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Dynamic adsorption and interfacial rheology of whey protein isolate at oil-water interfaces: Effects of protein concentration, pH and heat treatment. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2021.106640] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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37
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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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38
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Hydrophobicity, amphilicity, and flexibility: Relation between molecular protein properties and the macroscopic effects of surface activity. J Biotechnol 2021; 334:11-25. [PMID: 34015375 DOI: 10.1016/j.jbiotec.2021.05.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Revised: 04/16/2021] [Accepted: 05/05/2021] [Indexed: 11/24/2022]
Abstract
Their surface activity enables proteins to form and stabilize foam, which can be used for in situ product separation or foam fractionation. Thus, it would be highly desirable to predict the surface activity of proteins based on their molecular properties like hydrophobicity, amphilicity, or structure on primary, secondary, and tertiary level. Ionic strength and pH were adjusted to gain maximum surface activity. The surface activity decreased in the order α lactalbumin > β‑lactoglobulin > trypsinogen > papain. For the theoretical analysis, the database was extended by including 2 hydrophobins into the investigation, since they are known to exhibit an outstanding surface activity. No relation to the macroscopic behavior was found considering the hydrophobicity. I.e., the non-hydrophobins did not differ significantly from each other, and from the hydrophobins, one was significantly hydrophobic, and the other was significantly hydrophilic. Also, no relations were found considering the amphilicity of the secondary structure elements. However, taking into account the tertiary protein structure, it was found that for most of the proteins investigated, the presence of non-buried amphiphilic secondary structure elements in combination with a certain amount of flexibility correlates with the surface activity.
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39
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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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40
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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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41
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β-Lactoglobulin Adsorption Layers at the Water/Air Surface: 5. Adsorption Isotherm and Equation of State Revisited, Impact of pH. COLLOIDS AND INTERFACES 2021. [DOI: 10.3390/colloids5010014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The theoretical description of the adsorption of proteins at liquid/fluid interfaces suffers from the inapplicability of classical formalisms, which soundly calls for the development of more complicated adsorption models. A Frumkin-type thermodynamic 2-d solution model that accounts for nonidealities of interface enthalpy and entropy was proposed about two decades ago and has been continuously developed in the course of comparisons with experimental data. In a previous paper we investigated the adsorption of the globular protein β-lactoglobulin at the water/air interface and used such a model to analyze the experimental isotherms of the surface pressure, Π(c), and the frequency-, f-, dependent surface dilational viscoelasticity modulus, E(c)f, in a wide range of protein concentrations, c, and at pH 7. However, the best fit between theory and experiment proposed in that paper appeared incompatible with new data on the surface excess, Γ, obtained from direct measurements with neutron reflectometry. Therefore, in this work, the same model is simultaneously applied to a larger set of experimental dependences, e.g., Π(c), Γ(c), E(Π)f, etc., with E-values measured strictly in the linear viscoelasticity regime. Despite this ambitious complication, a best global fit was elaborated using a single set of parameter values, which well describes all experimental dependencies, thus corroborating the validity of the chosen thermodynamic model. Furthermore, we applied the model in the same manner to experimental results obtained at pH 3 and pH 5 in order to explain the well-pronounced effect of pH on the interfacial behavior of β-lactoglobulin. The results revealed that the propensity of β-lactoglobulin globules to unfold upon adsorption and stretch at the interface decreases in the order pH 3 > pH 7 > pH 5, i.e., with decreasing protein net charge. Finally, we discuss advantages and limitations in the current state of the model.
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42
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Stabilization of whey protein isolate-based emulsions via complexation with xanthan gum under acidic conditions. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2020.106365] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
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Zhao H, Li W, Chu W, Bollard M, Adão R, Schuck P. Quantitative Analysis of Protein Self-Association by Sedimentation Velocity. ACTA ACUST UNITED AC 2021; 101:e109. [PMID: 32614509 DOI: 10.1002/cpps.109] [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] [Indexed: 11/11/2022]
Abstract
Sedimentation velocity analytical ultracentrifugation is a powerful classical method to study protein self-association processes in solution based on the size-dependent macromolecular migration in the centrifugal field. This technique can elucidate the assembly scheme, measure affinities ranging from picomolar to millimolar Kd , and in favorable cases provide information on oligomer lifetimes and hydrodynamic shape. The present step-by-step protocols detail the essential steps of instrument calibration, experimental setup, and data analysis. Using a widely available commercial protein as a model system, the protocols invite replication and comparison with our results. A commentary discusses principles for modifications in the protocols that may be necessary to optimize application of sedimentation velocity analysis to other self-associating proteins. ©2020 Wiley Periodicals LLC. Basic Protocol 1: Measurement of external calibration factors Basic Protocol 2: Sedimentation velocity experiment for protein self-association Basic Protocol 3: Sedimentation coefficient distribution analysis in SEDFIT and isotherm analysis in SEDPHAT.
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Affiliation(s)
- Huaying Zhao
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland
| | - Wenqi Li
- National Protein Science Facility, School of Life Science, Tsinghua University, Beijing, China
| | - Wendan Chu
- National Protein Science Facility, School of Life Science, Tsinghua University, Beijing, China
| | - Mary Bollard
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland
| | - Regina Adão
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland
| | - Peter Schuck
- Dynamics of Macromolecular Assembly Section, Laboratory of Cellular Imaging and Macromolecular Biophysics, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland
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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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Keppler JK, Heyse A, Scheidler E, Uttinger MJ, Fitzner L, Jandt U, Heyn TR, Lautenbach V, Loch JI, Lohr J, Kieserling H, Günther G, Kempf E, Grosch JH, Lewiński K, Jahn D, Lübbert C, Peukert W, Kulozik U, Drusch S, Krull R, Schwarz K, Biedendieck R. Towards recombinantly produced milk proteins: Physicochemical and emulsifying properties of engineered whey protein beta-lactoglobulin variants. Food Hydrocoll 2021. [DOI: 10.1016/j.foodhyd.2020.106132] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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Isolation and Self-Association Studies of Beta-Lactoglobulin. Int J Mol Sci 2020; 21:ijms21249711. [PMID: 33352705 PMCID: PMC7766286 DOI: 10.3390/ijms21249711] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2020] [Revised: 12/15/2020] [Accepted: 12/17/2020] [Indexed: 12/31/2022] Open
Abstract
The aim of this study was to investigate isolated β-lactoglobulin (β-LG) from the whey protein isolate (WPI) solution using the column chromatography with SP Sephadex. The physicochemical characterization (self-association, the pH stability in various salt solutions, the identification of oligomeric forms) of the protein obtained have been carried out. The electrophoretically pure β-LG fraction was obtained at pH 4.8. The fraction was characterized by the matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF/TOF MS) technique. The use of the HCCA matrix indicated the presence of oligomeric β-LG forms, while the SA and DHB matrices enabled the differentiation of A and B isoforms in the sample. The impact of sodium chloride, potassium chloride, ammonium sulfate, and sodium citrate in dispersion medium on β-LG electrophoretic stability in solution was also studied. Type of the dispersion medium led to the changes in the isoelectric point of protein. Sodium citrate stabilizes protein in comparison to ammonium sulfate. Additionally, the potential of capillary electrophoresis (CE) with UV detection using bare fused capillary to monitor β-LG oligomerization was discussed. Obtained CE data were further compared by the asymmetric flow field flow fractionation coupled with the multi-angle light scattering detector (AF4-MALS). It was shown that the β-LG is a monomer at pH 3.0, dimer at pH 7.0. At pH 5.0 (near the isoelectric point), oligomers with structures from dimeric to octameric are formed. However, the appearance of the oligomers equilibrium is dependent on the concentration of protein. The higher quantity of protein leads to the formation of the octamer. The far UV circular dichroism (CD) spectra carried out at pH 3.0, 5.0, and 7.0 confirmed that β-sheet conformation is dominant at pH 3.0, 5.0, while at pH 7.0, this conformation is approximately in the same quantity as α-helix and random structures.
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Minić S, Annighöfer B, Hélary A, Hamdane D, Hui Bon Hoa G, Loupiac C, Brûlet A, Combet S. Effect of Ligands on HP-Induced Unfolding and Oligomerization of β-Lactoglobulin. Biophys J 2020; 119:2262-2274. [PMID: 33129832 DOI: 10.1016/j.bpj.2020.10.019] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/25/2020] [Accepted: 10/19/2020] [Indexed: 10/23/2022] Open
Abstract
To probe intermediate states during unfolding and oligomerization of proteins remains a major challenge. High pressure (HP) is a powerful tool for studying these problems, revealing subtle structural changes in proteins not accessible by other means of denaturation. Bovine β-lactoglobulin (BLG), the main whey protein, has a strong propensity to bind various bioactive molecules such as retinol and resveratrol, two ligands with different affinity and binding sites. By combining in situ HP-small-angle neutron scattering (SANS) and HP-ultraviolet/visible absorption spectroscopy, we report the specific effects of these ligands on three-dimensional conformational and local changes in BLG induced by HP. Depending on BLG concentration, two different unfolding mechanisms are observed in situ under pressures up to ∼300 MPa: either a complete protein unfolding, from native dimers to Gaussian chains, or a partial unfolding with oligomerization in tetramers mediated by disulfide bridges. Retinol, which has a high affinity for the BLG hydrophobic cavity, significantly stabilizes BLG both in three-dimensional and local environments by shifting the onset of protein unfolding by ∼100 MPa. Increasing temperature from 30 to 37°C enhances the hydrophobic stabilization effects of retinol. In contrast, resveratrol, which has a low binding affinity for site(s) on the surface of the BLG, does not induce any significant effect on the structural changes of BLG due to pressure. HP treatment back and forth up to ∼300 MPa causes irreversible covalent oligomerization of BLG. Ab initio modeling of SANS shows that the oligomers formed from the BLG-retinol complex are smaller and more elongated compared to BLG without ligand or in the presence of resveratrol. By combining HP-SANS and HP-ultraviolet/visible absorption spectroscopy, our strategy highlights the crucial role of BLG hydrophobic cavity and opens up new possibilities for the structural determination of HP-induced protein folding intermediates and irreversible oligomerization.
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Affiliation(s)
- Simeon Minić
- Université Paris-Saclay, Laboratoire Léon-Brillouin, UMR12 CEA-CNRS, CEA-Saclay, Gif-sur-Yvette CEDEX, France.
| | - Burkhard Annighöfer
- Université Paris-Saclay, Laboratoire Léon-Brillouin, UMR12 CEA-CNRS, CEA-Saclay, Gif-sur-Yvette CEDEX, France
| | - Arnaud Hélary
- Université Paris-Saclay, Laboratoire Léon-Brillouin, UMR12 CEA-CNRS, CEA-Saclay, Gif-sur-Yvette CEDEX, France
| | - Djemel Hamdane
- Laboratoire de Chimie des Processus Biologiques, CNRS-UMR 8229, Collège de France, Paris CEDEX 05, France
| | - Gaston Hui Bon Hoa
- National Institute of Health and Medical Research (INSERM), Paris, France
| | - Camille Loupiac
- Université de Bourgogne Franche-Comté, AgroSup Dijon, UMRA 02.102 Procédés Alimentaires et Microbiologiques, Equipe Physico-Chimie des Aliments et du Vin, Dijon, France
| | - Annie Brûlet
- Université Paris-Saclay, Laboratoire Léon-Brillouin, UMR12 CEA-CNRS, CEA-Saclay, Gif-sur-Yvette CEDEX, France
| | - Sophie Combet
- Université Paris-Saclay, Laboratoire Léon-Brillouin, UMR12 CEA-CNRS, CEA-Saclay, Gif-sur-Yvette CEDEX, France.
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Will JM, Erbacher C, Sperling M, Karst U. A mass spectrometry-based approach gives new insight into organotin-protein interactions. Metallomics 2020; 12:1702-1712. [PMID: 32930317 DOI: 10.1039/d0mt00171f] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In this study, the combination of speciation analysis and native mass spectrometry is presented as a powerful tool to gain new insight into the diverse interactions of environmentally relevant organotin compounds (OTCs) with proteins. Analytical standards of model proteins, such as β-lactoglobulin A (LGA), were thereby incubated with different phenyl- and butyltins. For adduct identification and characterization, the incubated samples were analyzed by inductively coupled plasma-mass spectrometry (ICP-MS) and electrospray ionization-mass spectrometry (ESI-MS) in combination with size exclusion chromatography (SEC). It allowed for a mild separation, which was most crucial to preserve the acid-labile organotin-protein adducts during their analyses. The binding of triorganotin compounds, such as triphenyltin, was shown to be sulfhydryl-directed by using cysteine-specific protein labeling. However, the sole availability of reduced cysteine residues in proteins did not automatically enable adduct formation. This observation complements previous studies and indicates the necessity of a highly specific binding pocket, which was identified for the model protein LGA via enzymatic digestion experiments. In contrast to triorganotins, their natural di- and mono-substituted degradation products, such as dibutyltin, revealed to be less specific regarding their binding to several proteins. Further, it also did not depend on reduced cysteine residues within the protein. In this context, they can probably act as linker molecules, interconnecting proteins, and leading to dimers and probably to higher oligomers. Furthermore, dibutyltin was observed to induce hydrolysis of the protein's peptide backbone at a specific site. Concerning unknown long-term toxic effects, our studies emphasize the importance of future studies on di- and mono-substituted OTCs.
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Affiliation(s)
- Jonas M Will
- Institute of Inorganic and Analytical Chemistry, University of Muenster, Corrensstr. 28/30, 48149 Muenster, Germany.
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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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50
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Zhou X, Wang C, Sun X, Zhao Z, Guo M. Effects of High Intensity Ultrasound on Physiochemical and Structural Properties of Goat Milk β-Lactoglobulin. MOLECULES (BASEL, SWITZERLAND) 2020; 25:molecules25163637. [PMID: 32785104 PMCID: PMC7464314 DOI: 10.3390/molecules25163637] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Revised: 07/21/2020] [Accepted: 08/09/2020] [Indexed: 11/21/2022]
Abstract
This study aimed to compare the effects of high intensity ultrasound (HIU) applied at various amplitudes (20~40%) and for different durations (1~10 min) on the physiochemical and structural properties of goat milk β-lactoglobulin. No significant change was observed in the protein electrophoretic patterns by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Deconvolution and second derivative of the Fourier transform infrared spectra (FTIR) showed that the percentage of β-sheet of goat milk β-lactoglobulin was significantly decreased while those of α-helix and random coils increased after HIU treatment The surface hydrophobicity index and intrinsic fluorescence intensity of samples was enhanced and increased with increasing HIU amplitude or time. Differential scanning calorimetry (DSC) results exhibited that HIU treatments improved the thermal stability of goat milk β-lactoglobulin. Transmission electron microscopy (TEM) of samples showed that the goat milk β-lactoglobulin microstructure had changed and it contained larger aggregates when compared with the untreated goat milk β-lactoglobulin sample. Data suggested that HIU treatments resulted in secondary and tertiary structural changes of goat milk β-lactoglobulin and improved its thermal stability.
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Affiliation(s)
- Xinhui Zhou
- Key Laboratory of Dairy Science, Northeast Agricultural University, Harbin 150030, China; (X.Z.); (C.W.); (X.S.); (Z.Z.)
| | - Cuina Wang
- Key Laboratory of Dairy Science, Northeast Agricultural University, Harbin 150030, China; (X.Z.); (C.W.); (X.S.); (Z.Z.)
- Department of Food Science, College of Food Science and Engineering, Jilin University, Changchun 130062, China
| | - Xiaomeng Sun
- Key Laboratory of Dairy Science, Northeast Agricultural University, Harbin 150030, China; (X.Z.); (C.W.); (X.S.); (Z.Z.)
| | - Zixuan Zhao
- Key Laboratory of Dairy Science, Northeast Agricultural University, Harbin 150030, China; (X.Z.); (C.W.); (X.S.); (Z.Z.)
| | - Mingruo Guo
- Key Laboratory of Dairy Science, Northeast Agricultural University, Harbin 150030, China; (X.Z.); (C.W.); (X.S.); (Z.Z.)
- Department of Nutrition and Food Sciences, College of Agriculture and Life Sciences, University of Vermont, Burlington, VT 05405, USA
- Correspondence: ; Tel.: +1-802-656-8168; Fax: +1-802-656-0001
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