REDUCTION OF IMMUNOREACTIVITY OF BOVINE SERUM-ALBUMIN CONJUGATED WITH COMB-SHAPED POLYETHYLENE-GLYCOL DERIVATIVES

Bovine serum albumin(BSA) was chemically modified with two types of comb-shaped copolymers of polyethylene glycol derivative and maleic anhydride, one with the molecular weight of 13,000 (activated PM13) and the other with 100,000 (activated PM100), to form PM13- and PM100-BSA. The immunoreactivity of BSA was markedly reduced by coupling with each modifier and was completely lost when 30% or 20% of amino groups in BSA were modified with activated PM13 or PM100, respectively. The esterase activity of PM13- and PM100-BSA without immunoreactivity were retained 63% and 93% of non-modified one, respectively. These results were discussed with those of modified-asparaginases(1). © 1993 Academic Press, Inc.