文献类型：期刊文献

英文题名：Effect of organic cosolvent on kinetic resolution of tert-leucine by penicillin G acylase from Kluyvera citrophila

作者：Liu, SL; Wei, DZ; Song, QX; Zhang, YW; Wang, XD

机构：[1]E China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China

年份：2006

卷号：28

期号：5

起止页码：285

外文期刊名：BIOPROCESS AND BIOSYSTEMS ENGINEERING

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000236490400002)】；

语种：英文

外文关键词：penicillin G acylase; resolution; organic cosolvent; tert-leucine

摘要：Penicillin G acylase (PGA) from Kluyvera citrophila immobilized on Amberzyml was used for enantioselective hydrolysis of N-phenylacetylated-dl-tert-leucine (N-Phac-DL-Tle) to produce L-tert-leucine (L-Tle). The effects of various organic cosolvents on hydrolysis of N-Phac-DL-Tle have been investigated in aqueous-cosolvent medium. It was founded that the rate of PGA-catalyzed reaction was significantly affected by the presence of 2% (v/v) organic cosolvent concentration. The initial rate fell with increasing logP of the cosolvent, but for logP values less than -0.24 the rate was faster than in purely aqueous medium. Additionally, the relative rate increases with the increase of dielectric constant (epsilon) of organic cosolvents. The yields of L-Tle in all aqueous-cosolvent systems were above 95% with the enantiomeric excess (ee) of > 99%.