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簡単なC ((sp((2)) -C ((sp(2)) 結合割れは,オキサール酸由来ラジカルで発生する

Robert W Molt¹, Alison M Lecher, Timothy Clark

¹Department of Chemistry and Chemical Biology, Indiana University-Purdue University , Indianapolis, Indiana 46202, United States.

Journal of the American Chemical Society

|February 24, 2015

まとめ

オキシラートデカルボキシラーゼ (OxDC) は,急性中間体経由でオキシラートの変換を容易にする. 電子の除去により,酸化酸におけるC−C結合の分裂に対するエネルギーバリアが大幅に低下し,OxDCに関する洞察を明らかにします.

科学分野:

バイオケミストリーバイオケミストリー
コンピューティング・ケミストリー
酵素学酵素学とは

背景:

オキシラートデカルボキシラーゼ (OxDC) は,マンガンに依存する酵素です.
OxDCの触媒機構,特に急性中間物質の役割は,まだ完全に理解されていません.

研究の目的:

水溶液中のオキサール酸由来ラジカルの構造と反応性に対する急性形成の影響を調査する.
OxDCの触媒メカニズムにおける妥当な中間物質を明らかにする.

主な方法:

カップリングクラスター理論の計算.
暗黙のソルベーションモデル.
オキサリック酸由来ラジカルの量子化学分析.

主要な成果:

C-C結合の裂解のための計算された自由エネルギーバリアは,オキサリック酸と比較して,過激な種にとって有意に減少した.
ラジカルカチオン形成は,C-C σ結合軌道にある単一の電子による長引のC-C結合 (1.7 Å) を引き起こした.
ニュートラルラジカルは同様のC-C結合の延長を示さなかった.

結論:

電子を除去してラジカルを形成する (陽子を失うか否か) は,非反応性C−C結合を裂くための潜在的な戦略である.
この研究は,OxDC触媒における中間物質の安定性と構造に関する化学的洞察を提供します.

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