title: The pH Dependence of Saccharides' Influence on Thermal Denaturation of Two Model Proteins Supports an Excluded Volume Model for Stabilization Generalized to Allow for Intramolecular Electrostatic Interactions.
abstract: The reversible thermal denaturation of apo α-lactalbumin (α-LA) and lysozyme was measured in the absence and presence of multiple concentrations of each of seven saccharides (glucose, galactose, fructose, sucrose, trehalose, raffinose, and stachyose) at multiple pH values. It was observed that with increasing pH, the absolute stability of α-LA decreased, whereas the stabilizing effect per mole of all saccharides increased, and that the absolute stability of lysozyme increased, whereas the stabilizing effect per mole of all saccharides decreased. All of the data may be accounted for quantitatively by straightforward electrostatic generalization of a previously introduced coarse-grained model for stabilization of proteins by sugars.
authors.affiliation: From the Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India and.
authors.forename: Ilyas
authors.initials: I
authors.lastname: Beg
authors.affiliation: the Laboratory of Biochemistry and Genetics, NIDDK, National Institutes of Health, Bethesda, Maryland 20892 minton@helix.nih.gov.
authors.forename: Allen P
authors.identifier: http://orcid.org/0000-0001-8459-1247
authors.initials: AP
authors.lastname: Minton
authors.affiliation: From the Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India and.
authors.forename: Asimul
authors.initials: A
authors.lastname: Islam
authors.affiliation: From the Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India and.
authors.forename: Md Imtaiyaz
authors.initials: MI
authors.lastname: Hassan
authors.affiliation: From the Centre for Interdisciplinary Research in Basic Sciences, Jamia Millia Islamia, Jamia Nagar, New Delhi 110025, India and fahmad@jmi.ac.in.
authors.forename: Faizan
authors.initials: F
authors.lastname: Ahmad
mesh_terms: D000818:Animals; D002241:Carbohydrates / Q000737:chemistry*; D002417:Cattle; D002645:Chickens; D006863:Hydrogen-Ion Concentration; D007768:Lactalbumin / Q000737:chemistry*; D008956:Models, Chemical; D009113:Muramidase / Q000737:chemistry*; D011489:Protein Denaturation; D055550:Protein Stability; D055672:Static Electricity
chemical_list: D002241:Carbohydrates; D007768:Lactalbumin; D009113:Muramidase
keywords: conformational change; excluded volume; oligosaccharide; osmolytes; protein stability; protein structure; thermal stability; thermodynamics