FUNCTIONAL-PROPERTIES OF BETA-LACTOGLOBULIN PHOSPHORYLATED IN THE PRESENCE OF DIFFERENT ALIPHATIC-AMINES

Phosphorylation of beta-lactoglobulin was carried out with 20, 40 and 80 mot POCl3/mol protein in the presence of different aliphatic amines . The physicochemical properties of the modified proteins changed acco rding to the nature of amine (tertiary or primary; shorter or longer a liphatic chain). The use of butylamine during the phosphorylation of b eta-lactoglobulin with POCl3 resulted in a low phosphorylation yield ( 2-4 mol P/mol protein), conferring, however, excellent foaming and emu lsifying properties to the phosphobutylated protein. The use of longer aliphatic primary amines (8-12 C) as bases and nucleophiles during th e phosphorylation of beta-lactoglobulin gave rise to low phosphorylati on, reduced solubility, poor foaming and emulsifying properties.