摘要
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)
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)
