期刊
MOLECULAR CATALYSIS
卷 448, 期 -, 页码 116-121出版社
ELSEVIER SCIENCE BV
DOI: 10.1016/j.mcat.2018.01.026
关键词
Ionic liquid; Candida antarctica lipase B; Resolution; (R,S)-1-(1-naphthyl)ethylamine
资金
- Prospective Joint Research Project of Jiangsu Province [BY2016030-12]
- Applied Basic Research Project of Changzhou City [CJ20159054]
The resolution of (R,S)-1-(1-naphthyl)ethylamine ((R,S)-NEA) by Candida antarctica lipase B (CALB) in ionic liquids (ILs) containing 1-alkyl-3-methylimidazolium cations ([C(n)mim](+)) and [Tf2N](-), [BF4](-), and [PF6](-) anions was investigated. When the alkyl chain on the cation contained less than six carbons, the lipase activity corresponded with the hydrophobicity of the ILs, but further increase in the chain length suppressed the enzyme activity. The enzyme activity decreased depending on the anion, where [Tf2N](-) > [PF6](-) > [BF4](-). The effects of acyl donors, pH, temperature, water activity, and substrate concentration on the resolution were determined. Under the optimal conditions, the conversion of (R,S)-NEA and enantiomer excess of (R)-n-octyl acyl-NEA was 49.3% and 99.2%, respectively. The resolution kinetics of (R,S)-NEA by CALB in [C(6)mim][Tf2N] were studied and a ping-pong mechanism with a two substrate inhibition model was selected. The kinetic parameters of the fitting results were as follows: Michaelis constant of (R,S)-NEA K-ja, 461.8 mmol/L; Michaelis constant of vinyl n-octanoateK(mb), 262.1 mmol/L; inhibition constant of (R,S)-NEA K-ia, 8737.2 mmol/L; inhibition constant of vinyl n-octanoateK(ib), 62336.8 mmol/L; maximum reaction rate r(max), 0.352 mmol/(mg min). Moreover, circular dichroism revealed that incubation of CALB in [C(6)mim] [Tf2N] resulted in increased beta-sheet content; its secondary structure was stable.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据