PHYSICOCHEMICAL CHARACTERIZATION OF MONOMERIC CHEMICALLY PHOSPHORYLATED CASEINS

Casein was phosphorylated under mild conditions with low molar ratios of POCl3 (25, 50 and 100 mole POCl3/mole protein) in the presence of equivalent amounts of triethylamine. Consequently, the resulting modified proteins (4-21 male P/mole protein) had increased negative charges, lower isoelectric points and existed mainly in a monomeric form. The extent of change in functional properties depended mainly on the degree of phosphorylation and the initial caseins.