PREPARATION AND ESTERIFICATION ACTIVITY OF POLY[(N-PROPIONYL)IMINOETHYLENE] MODIFIED LIPASE FROM CANDIDA-CYLINDRACEA

Candida cylindracea lipase was modified with a carboxylic acid-termina ted polymer of poly[(N-propionyl)iminoethylene] (1, M-n=4,280). Three samples of modified lipase (3) were prepared by changing the molar rat io of the N-succinimide activated ester of 1 (2) to lysyl groups ([2]/ [Lys]). The enzymatic activities of 3 for ester hydrolysis in an aqueo us solution and for esterification in benzene or chloroform were inves tigated. It was found that 3 was a more effective catalyst than unmodi fied and poly(ethylene glycol) modified lipase for both ester hydrolys is and esterification. Especially, in the case of 3a (average number o f 2 per molecule of enzyme = 2.6), its ester hydrolysis activity (in a buffer at pH 7) and esterification activity (in benzene) were about t hree times and ten times higher than those of the original lipase, res pectively. The effect of water in organic media on the enzymatic activ ity was also examined.