使用工程化细胞染色体P450 BM-3进行区域和酶选择性烯氧化
Matthew W Peters1, Peter Meinhold, Anton Glieder
1Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, USA.
Journal of the American Chemical Society
|October 30, 2003
概括
工程 Bacillus 巨细胞染色体 P450 BM-3 酶选择性地氧化线性基. 这些生物催化剂在全细胞系统中表现出高活性和酶选择性.
科学领域:
- 生物催化剂是一种生物催化剂.
- 酶工程是什么? 酶工程是什么?
- 有机化学 有机化学
背景情况:
- 来自Bacillus megaterium的细胞染色体P450 BM-3 (CYP102A1) 是一种强大的酶.
- 为选择性基化而设计P450对于绿色化学至关重要.
- 以前的方法往往缺乏区域和反选择性.
研究的目的:
- 为了设计Bacillus megaterium细胞染色体P450 BM-3进行选择性烯氧化.
- 使用大气氧来实现高的区域和酶选择性.
- 为了证明工程P450s在全细胞生物转化中的实用性.
主要方法:
- 使用定向进化和位点定向突变发生来修改P450 BM-3.
- 使用工程酶变异进行了基化反应.
- 使用表达工程P450s的大肠杆菌进行了全细胞生物转化.
主要成果:
- 变体9-10A-A328V氧化酸转化为S-2-octanol,具有40%的反体过量 (ee).
- 变体 1-12G 化基 (> 헥桑) 转化为 R-2 酒精,含有 40-55% ee.
- 工程生物催化剂表现出高活性 (高达400分钟−1) 和稳定性.
结论:
- 设计的P450 BM-3变种提供线性基的区域和酶选择性基化.
- 这些生物催化剂在像大肠杆菌这样的高水平表达系统中保持选择性.
- 开发的酶为生产性酒精提供了一条可持续的途径.
相关概念视频
03:08Hydroboration-Oxidation of Alkenes
In addition to the oxymercuration–demercuration method, which converts the alkenes to alcohols with Markovnikov orientation, a complementary hydroboration-oxidation method yields the anti-Markovnikov product. The hydroboration reaction, discovered in 1959 by H.C. Brown, involves the addition of a B–H bond of borane to an alkene giving an organoborane intermediate. The oxidation of this intermediate with basic hydrogen peroxide forms an alcohol.
02:36Regioselectivity and Stereochemistry of Hydroboration
A significant aspect of hydroboration–oxidation is the regio- and stereochemical outcome of the reaction.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
Hydroboration proceeds in a concerted fashion with the attack of borane on the π bond, giving a cyclic four-centered transition state. The –BH2 group is bonded to the less substituted carbon and –H to the more substituted carbon. The concerted nature requires the simultaneous addition of –H and –BH2 across the same face of the alkene giving syn stereochemistry.
02:13Reduction of Alkenes: Catalytic Hydrogenation
Alkenes undergo reduction by the addition of molecular hydrogen to give alkanes. Because the process generally occurs in the presence of a transition-metal catalyst, the reaction is called catalytic hydrogenation.
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the surface of...
Metals like palladium, platinum, and nickel are commonly used in their solid forms — fine powder on an inert surface. As these catalysts remain insoluble in the reaction mixture, they are referred to as heterogeneous catalysts.
The hydrogenation process takes place on the surface of...
02:17Reduction of Alkenes: Asymmetric Catalytic Hydrogenation
Catalytic hydrogenation of alkenes is a transition-metal catalyzed reduction of the double bond using molecular hydrogen to give alkanes. The mode of hydrogen addition follows syn stereochemistry.
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
The metal catalyst used can be either heterogeneous or homogeneous. When hydrogenation of an alkene generates a chiral center, a pair of enantiomeric products is expected to form. However, an enantiomeric excess of one of the products can be facilitated using an enantioselective reaction or an...
02:24Reduction of Alkynes to cis-Alkenes: Catalytic Hydrogenation
Introduction
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
Like alkenes, alkynes can be reduced to alkanes in the presence of transition metal catalysts such as Pt, Pd, or Ni. The reaction involves two sequential syn additions of hydrogen via a cis-alkene intermediate.
01:25Radical Anti-Markovnikov Addition to Alkenes: Overview
The addition of hydrogen bromide to alkenes in the presence of hydroperoxides or peroxides proceeds via an anti-Markovnikov pathway and yields alkyl bromides.