title: A molecular-thermodynamic model for the interactions between globular proteins in aqueous solutions: applications to bovine serum albumin (BSA), lysozyme, alpha-chymotrypsin, and immuno-gamma-globulins (IgG) solutions.
abstract: To investigate globular protein-protein and protein-salt interactions in electrolyte solutions, a potential of mean force including hard-core repulsion, van der Waals attraction and electric double layer repulsion is proposed in this work. Both van der Waals attraction and double-layer repulsion are represented using hard spheres with two-Yukawa tails. The explicit analytical solution of osmotic pressure is derived from the first-order mean spherical approximation. From the comparison between the calculated and experimental values of osmotic pressures for aqueous bovine serum albumin (BSA), lysozyme, alpha-chymotrypsin, and immuno-gamma-globulins (IgG) solutions, we found that the proposed model is adequate for the description of the interactions between proteins at low ionic strength and small self-association of protein molecules. At high ionic strength, the charge inversions of protein molecules should be taken into account.
authors.affiliation: Department of Chemical Engineering, Tsinghua University, Beijing 100084, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Jin
authors.forename: Yang-Xin
authors.initials: YX
authors.lastname: Yu
authors.forename: Guang-Hua
authors.initials: GH
authors.lastname: Gao
mesh_terms: D001665:Binding Sites; D002918:Chymotrypsin / Q000737:chemistry*; D004573:Electrolytes / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D007074:Immunoglobulin G / Q000737:chemistry*; D008954:Models, Biological; D008958:Models, Molecular; D009113:Muramidase / Q000737:chemistry*; D009994:Osmolar Concentration; D009997:Osmotic Pressure; D011485:Protein Binding; D012492:Salts / Q000737:chemistry; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013499:Surface Properties; D013816:Thermodynamics; D014867:Water / Q000737:chemistry
chemical_list: D004573:Electrolytes; D007074:Immunoglobulin G; D012492:Salts; D012996:Solutions; D014867:Water; D012710:Serum Albumin, Bovine; D009113:Muramidase; D002918:Chymotrypsin; C117608:alpha-chymotrypsin