エンジニアリングされたサイトクロームP450 BM-3によるレジオおよびエナチオセレクティブアルカンの水酸化
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
まとめ
エンジニアリングされたバシルス・メガテリウム・サイトクロームP450 BM-3酵素は,選択的に線形アルケンを水酸化する. これらの生物触媒は,全細胞系において高い活性とエナチオセレクティブ性を示しています.
科学分野:
- バイオカタリシス バイオカタリシス
- 酵素工学とは
- 有機化学 オーガニック・ケミストリー
背景:
- バシルス・メガテリウムからのサイトクロームP450BM-3 (CYP102A1) は強力な酵素です.
- 選択的アルカン水酸化のためのP450sのエンジニアリングは,グリーン化学にとって非常に重要です.
- 以前の方法は,しばしば地域およびエナチオセレクティブ性が欠けている.
研究 の 目的:
- バシルス・メガテリウム・サイトクロームP450 BM-3を選択性アルカン・ヒドロキシル化のために設計する.
- 大気中の酸素を用いて高い地域およびエナチオセレクティビティを達成する.
- エンジニアリングされたP450sが全細胞生物変異における有用性を実証するために.
主な方法:
- 誘導進化と局所誘導変異は,P450 BM-3を改変するために使用されました.
- アルケンの水酸化反応は,エンジニアリングされた酵素の変種を使用して行われました.
- エンジニアリングされたP450sを発現するEscherichia coliを使用して,全細胞バイオトランスフォーメーションが行われました.
主要な成果:
- 変種 9-10A-A328V ハイドロキシルオクタンからS-2-オクタノールに40パーセントのエナティオメール過量 (ee) を含む.
- 変種 1-12G 水酸化アルカン (>ヘクサン) からR-2-アルコールに 40-55% ee.
- エンジニアリングバイオカタリストは,高い活性 (最大400分−1) と安定性を示した.
結論:
- エンジニアリングされたP450 BM-3の変種は,線形アルケンの地域およびエナチオ選択的水酸化を提供します.
- これらの生物触媒は,E. coliのような高レベルの発現系において選択性を維持する.
- 開発された酵素は,キラルアルコールを生産するための持続可能な経路を提供します.
関連する概念動画
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.