Modification of L-asparaginase with Colominic Acid and the New Characteristics of the Modified Enzyme
多聚唾液酸对L-天冬酰胺酶的修饰及修饰酶特性研究

The colominlc acid was covalently coupled to L-asparaginase molecule by reductive amination. Depending on the molar ratios of colominic acid-asparaginase (301,501 and 1001),a modified enzyme molecule contained 4.7,7.2 and 12 colominic acid molecule,they retained 58%,56% and 33.2% of the initial asparaginase activity,respectively. In comparison with the native enzyme, modified enzyme had lower immunogenicity and antigenicity,longer half-life time (in uitro ),more resistance ability to trypsin proteolysis, and similar Km value for L-asparagine.