水素結合は,光活性黄色タンパク質染色体の興奮状態の崩壊を制御する

Martial Boggio-Pasqua¹, Michael A Robb, Gerrit Groenhof

¹Laboratoire de Chimie et Physique Quantiques, IRSAMC, CNRS et Universite de Toulouse, Toulouse, France.

Journal of the American Chemical Society

|September 5, 2009

まとめ

水中の光活性黄色タンパク質の染色体類は,主に単一結合の光イソメリゼーションを受けます. 超高速溶媒の再編成は,D2Oが興奮状態の寿命を増加させ,効率的な興奮状態の衰退を助けます.

科学分野:

フォトケミストリーフォトケミストリー
バイオフィジックス生物物理学
コンピューティング・ケミストリー

背景:

フォトアクティブイエロータンパク質 (PYP) は,フォトイソメリゼーションを研究するためのモデルシステムです.
異なる環境における染色体の行動を理解することは,タンパク質の機能にとって極めて重要です.

研究の目的:

水中のPYP染色体アナログの興奮状態ダイナミクスを調査する.
溶媒とタンパク質残留物の光異性化経路における役割を明らかにする.

主な方法:

興奮状態のダイナミクスシミュレーション.
潜在エネルギー表面と水素結合相互作用の分析.
水性およびD2O溶媒効果の比較.

主要な成果:

水中の単一結合のフォトイソメリゼーションが優勢で,二重結合のイソメリゼーションとは対照的です.
シングル・ボンドとダブル・ボンドの両方の歪んだ状態からの効率的な興奮状態の衰退.
溶媒の再編成と水素結合による歪んだ状態の安定化.
水と比較して,D2Oの興奮状態の寿命が長くなっています.

結論:

溶媒の再編成は,興奮状態の腐敗経路に著しく影響を与えます.
特定のタンパク質残留物 (Arg52,Tyr42,Glu46) は,PYPにおけるイソメリゼーションとデアクティベーションを調節する.
タンパク質環境は,染色体光異性化ダイナミクスを微調整する.

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