Itk SH2領域におけるプロリルイミド結合のCis/Transイソメリゼーションによって調節されたリガンド特異性:定量的なNMR研究
Patrick J Breheny1, Alain Laederach, D Bruce Fulton
1Department of Biochemistry, Biophysics and Molecular Biology, Program of Bioinformatics and Computational Biology, Iowa State University, Ames, Iowa 50011, USA.
Journal of the American Chemical Society
|December 18, 2003
まとめ
インタールイキン-2チロシンキナーゼ (Itk) SH2ドメインは,異なるリガンドを結合するためにシス/トランスイソメリゼーションを使用します. この研究では,SH3ドメインとフォスフォペプチドリガンドに対する明確な好みを明らかにし, afinitiesを定量化しています.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 構造生物学 構造生物学とは
背景:
- インターレウキン-2チロシンキナーゼ (Itk) Srcホモロジー2 (SH2) ドメインは,フォスフォチロシンを含むペプチドとItk Srcホモロジー3 (SH3) ドメインの両方に結合します.
- リガンド結合特異性は,Itk SH2ドメイン内のAsn286-Pro287イミド結合のシス/トランスイソメリゼーションによって調節される.
研究 の 目的:
- Itk SH2ドメインの異なるコンフォマーに対するリガンド afinitiesを定量化するための新しい方法を開発し,適用する.
- Itk SH2ドメインのcisおよびtransコンフォマーにおける,その既知のリガンドに対する異なる結合親和性を解明する.
主な方法:
- 化学的なシフトの混乱とクロスピークの体積分析を活用した.
- フォスフォペプチドとItk SH3ドメインの結合親和度をItk SH2ドメインのcisおよびtransコンフォマーに測定した.
主要な成果:
- シスイミド結合コンフォーマーは,トランスコンフォーマと比較して,Itk SH3ドメインに対する3.5倍以上の親和性を示した.
- トランスコンフォマーには,シスコンフォマーよりも,フォスフォペプチドリガンドに対する4倍以上の親和性が示された.
結論:
- この研究は,Itk SH2ドメインコンフォーマーの異なるリガンド結合特性を定量的に実証しています.
- 開発された方法論は,分子スイッチを使用した構成的に異質なシステムを分析するための一般的なアプローチを提供します.
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