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Nogueira MH, Ben-Harb S, Schmutz M, Doumert B, Nasser S, Derensy A, Karoui R, Delaplace G, Peixoto PP. Multiscale quantitative characterization of demineralized casein micelles: How the partial excision of nano-clusters leads to the aggregation during rehydration. Food Hydrocoll 2020. [DOI: 10.1016/j.foodhyd.2020.105778] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Sugar type matters in spray drying: Homogeneous distribution in milk powder favors repulsive interactions between proteins. FOOD STRUCTURE-NETHERLANDS 2019. [DOI: 10.1016/j.foostr.2019.100132] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Peixoto PDS, Trivelli X, André C, Moreau A, Delaplace G. Formation of β-Lactoglobulin Aggregates from Quite, Unfolded Conformations upon Heat Activation. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:446-452. [PMID: 30565468 DOI: 10.1021/acs.langmuir.8b03459] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
In presence of calcium ions, β-lactoglobulin (BLG) unfolds and subsequently aggregates after heating. This process has important pharmaceutical and agroalimentary applications. Nowadays, the molecular mechanism of unfolding and BLG aggregation, and the role of calcium in the mechanism, is poorly understood. Actually, in most studies, data have been acquired at room temperature, after heating and after aggregation, which makes it difficult to establish a clear causal-temporal relation between calcium binding, heat, and aggregation. Thus, the goal of the present study is to get accurate, nanoscale data about the molecular events leading to BLG unfolding and calcium-dependent aggregation. The molecular transformation of BLG during heating has been investigated, using the NMR pulse field gradient technique, operating in a high field (900 MHz). Thanks to this technique, the molecular conformation of newly formed unfolded BLG molecules can be distinguished in a large pool of native ones. The present work shows that BLG at neutral pH at 65 °C displays fast, cooperative-like unfolding, in which no long-lived intermediary state (as a molten globule one) is detected, before aggregation. These data also indicate that calcium ions bind unfolded BLG in specific sites which might be a necessary feature to form the aggregate. Finally, these data also provide an NMR-based methodology to monitor the rate of protein unfolding using NMR.
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Affiliation(s)
- Paulo D S Peixoto
- Univ. Lille, UMR 8207-UMET-Unité Matériaux et Transformations , 59000 Lille , France
- INRA , 59000 Lille , France
| | - Xavier Trivelli
- Université de Lille, CNRS, UMR 8576-UGSF-Unité de Glycobiologie Structurale et Fonctionnelle , 59655 Lille , France
| | - Christophe André
- Univ. Lille, UMR 8207-UMET-Unité Matériaux et Transformations , 59000 Lille , France
- INRA , 59000 Lille , France
- UC Lille, HEI, Laboratoire de Génie des Procédés , 59046 Lille , France
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Trovato F, Fumagalli G. Molecular simulations of cellular processes. Biophys Rev 2017; 9:941-958. [PMID: 29185136 DOI: 10.1007/s12551-017-0363-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Accepted: 11/19/2017] [Indexed: 12/12/2022] Open
Abstract
It is, nowadays, possible to simulate biological processes in conditions that mimic the different cellular compartments. Several groups have performed these calculations using molecular models that vary in performance and accuracy. In many cases, the atomistic degrees of freedom have been eliminated, sacrificing both structural complexity and chemical specificity to be able to explore slow processes. In this review, we will discuss the insights gained from computer simulations on macromolecule diffusion, nuclear body formation, and processes involving the genetic material inside cell-mimicking spaces. We will also discuss the challenges to generate new models suitable for the simulations of biological processes on a cell scale and for cell-cycle-long times, including non-equilibrium events such as the co-translational folding, misfolding, and aggregation of proteins. A prominent role will be played by the wise choice of the structural simplifications and, simultaneously, of a relatively complex energetic description. These challenging tasks will rely on the integration of experimental and computational methods, achieved through the application of efficient algorithms. Graphical abstract.
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Affiliation(s)
- Fabio Trovato
- Department of Mathematics and Computer Science, Freie Universität Berlin, Arnimallee 6, 14195, Berlin, Germany.
| | - Giordano Fumagalli
- Nephrology and Dialysis Unit, USL Toscana Nord Ovest, 55041, Lido di Camaiore, Lucca, Italy
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Potential of Casein as a Carrier for Biologically Active Agents. Top Curr Chem (Cham) 2017; 375:71. [PMID: 28712055 PMCID: PMC5511616 DOI: 10.1007/s41061-017-0158-z] [Citation(s) in RCA: 100] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/29/2017] [Indexed: 02/07/2023]
Abstract
Casein is the collective name for a family of milk proteins. In bovine milk, casein comprises four peptides: αS1, αS2, β, and κ, differing in their amino acid, phosphorus and carbohydrate content but similar in their amphiphilic character. Hydrophilic and hydrophobic regions of casein show block distribution in the protein chain. Casein peptides carry negative charge on their surface as a result of phosphorylation and tend to bind nanoclusters of amorphous calcium phosphate. Due to these properties, in suitable conditions, casein molecules agglomerate into spherical micelles. The high content of casein in milk (2.75 %) has made it one of the most popular proteins. Novel research techniques have improved understanding of its properties, opening up new applications. However, casein is not just a dietary protein. Its properties promise new and unexpected applications in science and the pharmaceutical and functional food industries. One example is an encapsulation of health-related substances in casein matrices. This review discusses gelation, coacervation, self-assembly and reassembly of casein peptides as means of encapsulation. We highlight information on encapsulation of health-related substances such as drugs and dietary supplements inside casein micro- and nanoparticles.
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Mesoporous calcium phosphate using casein as a template: Application to bovine serum albumin sorption. Colloids Surf B Biointerfaces 2017; 158:480-487. [PMID: 28735220 DOI: 10.1016/j.colsurfb.2017.07.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Revised: 05/31/2017] [Accepted: 07/05/2017] [Indexed: 12/28/2022]
Abstract
Mesoporous hydroxyapatites were synthesized at room temperature using casein as a template, and key experimental factors, such as casein concentration, pH and extraction of casein in the final solids by washing and thermal treatment, were systematically investigated. The X-Ray Diffraction (XRD) patterns confirmed the synthesis of well-crystallized hydroxyapatite. The N2 adsorption/desorption isotherms were in agreement with the formation of mesoporous hydroxyapatite with a maximum surface area of 106m2g-1. Infrared spectroscopy and thermogravimetry analysis were performed to investigate the extraction of casein in water in the post-synthesis stage. Pure mesoporous hydroxyapatite exhibited good BSA adsorption capacity higher than the one obtained for conventional hydroxyapatite.
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Thévenot J, Cauty C, Legland D, Dupont D, Floury J. Pepsin diffusion in dairy gels depends on casein concentration and microstructure. Food Chem 2017; 223:54-61. [DOI: 10.1016/j.foodchem.2016.12.014] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/06/2016] [Accepted: 12/07/2016] [Indexed: 01/23/2023]
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Peixoto PDS, Tavares GM, Croguennec T, Nicolas A, Hamon P, Roiland C, Bouhallab S. Structure and Dynamics of Heteroprotein Coacervates. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:7821-7828. [PMID: 27352848 DOI: 10.1021/acs.langmuir.6b01015] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Under specific conditions, mixing two oppositely charged proteins induces liquid-liquid phase separation. The denser phase, or coacervate phase, can be potentially applied as a system to protect or encapsulate different bioactive molecules with a broad range of food and/or medical applications. The optimization of the design and efficiency of such systems requires a precise understanding of the structure and the equilibrium of the nanocomplexes formed within the coacervate. Here, we report on the nanocomplexes and the dynamics of the coacervates formed by two well-known, oppositely charged proteins β-lactoglobulin (β-LG, pI ≈ 5.2) and lactoferrin (LF, pI ≈ 8.5). Fluorescence recovery after photobleaching (FRAP) and solid-state nuclear magnetic resonance (NMR) experiments indicate the coexistence of several nanocomplexes as the primary units for the coacervation. To our knowledge, this is the first evidence of the occurrence of an equilibrium between quite unstable nanocomplexes in the coacervate phase. Combined with in silico docking experiments, these data support the fact that coacervation in the present heteroprotein system depends not only on the structural composition of the coacervates but also on the association rates of the proteins forming the nanocomplexes.
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Affiliation(s)
| | - Guilherme M Tavares
- STLO, UMR1253, INRA, Agrocampus Ouest, 35000 Rennes, France
- Laboratory of Research in Milk Products, Universidade Federal de Viçosa , BR-36570 Viçosa, Brazil
| | | | | | | | - Claire Roiland
- Institut des Sciences Chimiques de Rennes, UMR CNRS 6226, Université de Rennes 1, CS 74205 Rennes, France
| | - Saïd Bouhallab
- STLO, UMR1253, INRA, Agrocampus Ouest, 35000 Rennes, France
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Mody P, Hart C, Romano S, El-Magbri M, Esson MM, Ibeh T, Knowlton ED, Zhang M, Wagner MJ, Hartings MR. Protein-based ferrogels. J Inorg Biochem 2016; 159:7-13. [DOI: 10.1016/j.jinorgbio.2016.02.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Revised: 01/22/2016] [Accepted: 02/10/2016] [Indexed: 11/16/2022]
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