サイトクロームP450カムの活性部位およびその部位指向変異体の水素結合相互作用
T Deng1, I D Macdonald, M C Simianu
1Department of Chemistry, Marquette University, Wehr Chemistry Building, P.O. Box1881 (535 North 14th Street, 53233), Milwaukee, Wisconsin 53201-1881, USA.
Journal of the American Chemical Society
|July 18, 2001
まとめ
共振ラーマン光譜法により,シトクロームP450camのシアン酸添加物は,線形コンフォマーと曲線コンフォマーの両方を形成することを明らかにします. 曲った形は,H結合ドナーの影響を受け,基質結合に対する方向性を変化させ,ヘム構造に影響を与えます.
科学分野:
- バイオケミストリー バイオケミストリー
- スペクトロスコーピーは,スペクトロスコーピーを用います.
- 酵素学 酵素学とは
背景:
- サイトクロームP450camは,薬物の代謝における重要な酵素です.
- アクティブサイトダイナミクスを理解することは,酵素の機能の鍵です.
- シアン酸アダクトは,ヘム環境の相互作用のためのユニークな探査機を提供します.
研究 の 目的:
- サイトクロームP450camの活性部位ヘム構造を調査する.
- FeCN断片とH結合ドナーとの相互作用を調査する.
- 顕微鏡を用いて基板結合時の形状の変化を明らかにする.
主な方法:
- 共振ラーマン光譜を用いた.
- サイトクロームP450カムおよびその変異体 (T252A,D251N) のシアン誘導体に関する研究が行われました.
- サブストラットフリー形態とカンファー結合形態の両方を分析した.
主要な成果:
- シアン酸アドクトは,COとNOアドクトとは異なり,線形コンフォマーと曲線コンフォマーの両方を表しています.
- 曲ったコンファーマーはH結合ドナー相互作用に起因する.
- 基板フリー形態のスペクトルカップリングは,基板結合形態では存在しないので,形状的シフトが示唆される.
結論:
- サイトクロームP450カムの活性部位は,独特のFeCN形状に対応しています.
- H-ボンドのドナーは,ヘム-シアン化物の相互作用に著しく影響します.
- サブストラット結合は,ボンドコンフォマーを方向転換し,酵素ダイナミクスと潜在的にサブストラット処理に影響を与えます.
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