title: Influence of the ionic strength on the heat-induced aggregation of the globular protein beta-lactoglobulin at pH 7.
abstract: The influence of the ionic strength on the structure of beta-lactoglobulin aggregates formed after heating at pH 7 has been studied using static and dynamic light scattering. The native protein depletion has been monitored using size exclusion chromatography. Above a critical association concentration (CAC) well-defined clusters are formed containing about 100 monomers. The CAC increases with decreasing ionic strength. The so-called primary aggregates associate to form self similar semi-flexible aggregates with a large scale structure that is only weakly dependent on the ionic strength. The local density of the aggregates increases with increasing ionic strength. At a critical gel concentration, Cg, the size of the aggregates diverges. Cg decreases from 100 g/l without added salt to 1 g/l at 0.4M NaCl. For C > Cg the system gels except at high ionic strength close to Cg where the gels collapse under gravity and a precipitate is formed.
authors.affiliation: Polymères, Colloïdes, Interfaces, UMR CNRS, Université du Maine, Av. Olivier Messiaen 72085 Le Mans Cedex 9, France.
authors.forename: Karine
authors.initials: K
authors.lastname: Baussay
authors.forename: Christel Le
authors.initials: CL
authors.lastname: Bon
authors.forename: Taco
authors.initials: T
authors.lastname: Nicolai
authors.forename: Dominique
authors.initials: D
authors.lastname: Durand
authors.forename: Jean-Pierre
authors.initials: JP
authors.lastname: Busnel
mesh_terms: D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007782:Lactoglobulins / Q000737:chemistry*; D009994:Osmolar Concentration
chemical_list: D007782:Lactoglobulins