Dephosphorylation of αS- and κ-Caseins and Its Effect on Micelle Stability in the κ-αS-Casein System

Abstract

Enzymatic dephosphorylation of [alpha]s - and [kappa]-caseins does not impair the formation of a stoichiometric complex of these proteins. In the presence of Ca ions, dephosphorylated [alpha]s-casein is only slightly stabilized by [kappa] -casein against precipitation; whereas dephosphorylation of [kappa]-casein alone yields [alpha]s - [kappa]-casein micelles which are stabile against Ca ion precipitation. Esterified calcium-phosphate linkages are formed among [alpha]s - [kappa] -casein complexes (in the absence of Ca) readily form indicating that the formation of H bonds and interaction of abundant non-polar side chains are responsible for complex formation.