EFFECT OF MODIFIER ON ENZYMATIC FUNCTION OF POLY[(N-ACYLIMINO)ETHYLENE]-MODIFIED LIPASES IN ORGANIC-SOLVENTS

Candida cylindracea lipase was modi fled by carboxylic-acid-terminated polymers having different molecular weights, i.e., poly[(N-acetylimin o)ethylene] (2a), poly[(N-propionylimino)ethylene] (2b) and poly[(N-is obutyrylimino)ethylene] (2c). The effect of N-acyl substituent of 2a-c on the enzymatic activity of modified lipase (4) for hydrolysis of ol ive oil and p-nitrophenyl propionate in an aqueous solution and for es terification between n-amyl alcohol and caprylic acid in chloroform, b enzene, toluene, and isooctane was examined by using 2a-c of a similar MW (5000 similar to 6000). It was found that the active site reactivi ty of lipase was not as influenced by the chemical modification of lip ase in an aqueous medium, and that the rates of esterification were re markably enhanced, especially in benzene and toluene, by modification with 2b or 2c compared with the native lipase. The effects of the mole cular weight of 2a-c and the average number of 2a-c per molecule of li pase on the enzymatic activity were also investigated.