5'-デオキシアデノシル基の内部自由度,構造モチーフ,構成エネルギー:アデノシルコバラミン依存酵素の機能への影響. 計算による研究である
Dmitry V Khoroshun1, Kurt Warncke, Shyue-Chu Ke
1Cherry L. Emerson Center for Scientific Computation, Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA.
Journal of the American Chemical Society
|January 9, 2003
まとめ
計算による研究は,その間に5が5であったことを明らかにしています.
科学分野:
- コンピューティング・ケミストリー
- 生物物理化学 生物物理化学
- 量子化学とは,量子化学である.
背景:
- 5'-デオキシアデノシルラジカルは,生物学的システム,特にコエンザイムB12依存酵素内のラジカル化学の重要な中間物質です.
- その潜在エネルギー表面の理解は,反応機構と酵素機能の解明に不可欠です.
研究 の 目的:
- ガス相における自由5'-デオキシアデノシル基の潜在エネルギー表面を計算的に探求する.
- その反応性と安定性を支配する重要な相互作用と構成変化を特定する.
- 計算上の発見とアデノシルコバラミンの実験的観測を相関させる.
主な方法:
- 密度関数理論 (DFT) と第2次モラー・プレセット乱理論 (MP2) について説明します.
- 6-31G(d) と6-31++G(d,p) のベースセットを計算に使用した.
- 水素結合とステリック効果を含む,魅力と排斥の相互作用の分析.
主要な成果:
- 5',8回転経路はエネルギー的に好ましい (外熱は ~20 kcal/mol) が,運動的に阻害されている.
- ヒドロキシル群とアデニンN3の間の水素結合は,開いた同位体において重要な吸引力となる.
- リボゼ-アデニンの回転は,排斥と引き寄せの相互作用により,エネルギーに大きな影響を及ぼします.
結論:
- グリコシル結合の回転は,酵素における長距離の急性移転の主な要因である可能性があります.
- グリコシル回転とCo-C結合の割れ間のシナージは,アデノシルコバラミンにおけるラビライゼーションを説明する可能性がある.
- タンパク質環境の影響については,さらなる調査が必要である.
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