TITLE:
How can aprotic ionic liquids affect enzymatic enantioselectivity?
AUTHORS:
Hidetaka Noritomi, Hideki Chiba, Manabu Kikuta, Satoru Kato
KEYWORDS:
α-Chymotrypsin; Enantioselectivity; Esterification; Aprotic Ionic Liquid
JOURNAL NAME:
Journal of Biomedical Science and Engineering,
Vol.6 No.10,
October
8,
2013
ABSTRACT: The enantioselectivity of α-chymotrypsin in the esterification of N-acetyl-tryptophan with ethanol was examined in aprotic ionic liquids. The enantioselectivity was found to be strongly affected by a kind of solvent, water content, and reaction temperature. The (kcatKM)L/(kcat/KM)D ratio in 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)imide ([C2mim][FSI]) containing 1.0% (v/v) water at 25°C exhibits 32,000, while that in 1-ethyl-3-methylimidazolium tetrafluoroborate ([C2mim][BF4]) containing 1.0% (v/v) water at 25°C shows 190. The (kcat/KM)L/(kcat/KM)D ratio in [C2mim] [BF4] at 25°C varies from 190 at 1.0% (v/v) water to 65000 at 5.0% (v/v) water. Moreover, the (kcat/KM)L/ (kcat/KM)