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Electrostatic properties of bovine β‐lactoglobulin
Author(s) -
Fogolari Federico,
Ragona Laura,
Licciardi Stefania,
Romagnoli Silvia,
Michelutti Roberta,
Ugolini Raffaella,
Molinari Henriette
Publication year - 2000
Publication title -
proteins: structure, function, and bioinformatics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.699
H-Index - 191
eISSN - 1097-0134
pISSN - 0887-3585
DOI - 10.1002/(sici)1097-0134(20000601)39:4<317::aid-prot50>3.0.co;2-w
Subject(s) - beta lactoglobulin , bovine milk , chemistry , whey protein , chromatography
Abstract Bovine β‐Lactoglobulin (BLG) has been studied for many decades, but only recently structural data have been obtained, making it possible to simulate its molecular properties. In the present study, electrostatic properties of BLG are investigated theoretically using Poisson‐Boltzmann calculations and experimentally following pH titration via NMR. Electrostatic properties are determined for several structural models, including an ensemble of NMR structures obtained at low pH. The changes in electrostatic forces upon changes in ionic strength, solvent dielectric constant, and pH are calculated and compared with experiments. pK a s are computed for all titratable sites and compared with NMR titration data. The analysis of theoretical and experimental results suggests that (1) there may be more than one binding sites for negatively charged ligands; (2) at low pH the core of the molecule is more compact than observed in the structures obtained via restrained molecular dynamics from NMR data, but loop and terminal regions must be disordered. Proteins 2000;39:317–330. © 2000 Wiley‐Liss, Inc.