2-Propanol treatment of Candida rugosa lipase and its hydrolytic activity

We studied the effects of the 2-propanol treatment of Candida rugosa lipase (CRL) by the addition of 2-propanol in the range of 0–35 ml against 25 ml of the solution extracted from 5 g of CRL on its hydrolytic activity, stereoselectivity, and recovered protein. Consequently, the following four results were revealed: (1) the highest hydrolytic specific activity against p-nitrophenyl acetate (PNPA) and the p-nitrophenyl esters of a series of straight-chain carboxylic acids was shown by CRL treated with 20 ml 2-propanol; (2) the total activity for PNPA monotonously increased up to 15 ml of 2-propanol addition while over 15 ml of 2-propanol addition resulted in a drastic decrease in total activity; (3) stereoselectivity for methyl 2-phenylpropanoate was improved in accordance with the increase in the 2-propanol added, and 20 ml of 2-propanol addition produced an E value over 500; and (4) recovered protein decreased in accordance with the volume of 2-propanol added and significantly decreased, especially at 5 ml and over 15 ml of 2-propanol addition.