単回転アルファヘリクスの安定性について:単回転対多回転変形問題

James P Snyder¹, Ami S Lakdawala, Michael J Kelso

¹Department of Chemistry, Emory University, Atlanta, Georgia 30322, USA. snyder@euch4e.chem.emory.edu

Journal of the American Chemical Society

|January 16, 2003

まとめ

この研究は,パラジウムサイクルペプチドの単一アルファヘリックスモデルに挑戦しています. 構成分析は,平均的なNMRデータから,単一のヘリックスではなく,複数の急速に相互変換する構造を明らかにします.

科学分野:

協調化化学について
計算化学はコンピュータ化学である.
生物物理化学生物物理化学とは

背景:

ペンタペプチドのパラジウム (II) 複合化により,特定の形状が誘発される.
以前の研究では,2D NMRとシミュレート annealingに基づいた[Pd(en) ((ペプチド) ]2+のための単一のアルファヘリックスを示唆しました.

研究の目的:

パラジアムサイクルペンタペプチド [Pd(en) ((ペプチド) ]2+の溶液構成を再評価する.
平均的なNMRデータから単一の形状の仮定を調査する.

主な方法:

Pd2+イオンに対するAMBER*パラメータの開発.
分子ダイナミクスシミュレーションを用いた広範な形状調査.
平均の2D NMRデータを複数の形状に分解する.

主要な成果:

[Pd(en) ((ペプチド) ]2+複合体は,8つの異なる形状の均衡として存在する.
特定された形状のいずれも,正規のアルファヘリックスを表していません.
わずかな形状 (3%) は,アルファヘリックスと構造的に類似している.

結論:

[Pd(en) ((ペプチド) ]2+の平均化されたNMRデータから単一の形状を仮定することは誤りである.
形状分解は,NMRスペクトルの正確な解釈に不可欠です.
パラジウム媒介ペプチドサイクリングは,構造のダイナミックなアンサンブルを生成します.

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