陽子検知型固体NMRは,7つの螺旋状のトランスメブランタンパク質プロテオロドプシン内の膜内極性ネットワークを明らかにします
Meaghan E Ward1, Lichi Shi, Evelyn Lake
1Department of Physics and Biophysics Interdepartmental Group, University of Guelph, Guelph, Ontario N1G 2W1, Canada.
Journal of the American Chemical Society
|September 17, 2011
まとめ
高解像度のNMRは,膜プロトンポンプであるプロテオロドプシン (PR) の溶媒にさらされた領域を明らかにした. ヘリックスGは,キー残留物とLys231を含んでアクセス可能であり,陽子輸送における役割をサポートしています.
科学分野:
- 構造生物学 構造生物学とは
- バイオフィジックス 生物物理学
- 膜タンパク質 膜タンパク質
背景:
- プロテオロドプシン (PR) は7ヘリクルの統合膜プロトンポンプです.
- PRの溶媒アクセシビリティを理解することは,その陽子輸送機構の解明に不可欠です.
研究 の 目的:
- 先進的なNMR技術を使用して,プロテオロドプシンの溶媒にさらされた領域を調査する.
- 陽子の転位に関与する残留物を特定し,PRの構造と機能と関連付けます.
主な方法:
- 高解像度プロトン検出多次元NMRスペクトロスコーピー.
- デュテラート媒介と陽子逆交換を用いてPRサンプルを準備する.
- 共振配分のための3次元プロトン検知化学シフト相関スペクトロスコーピー.
主要な成果:
- PR.における溶媒に曝露された残留物に対する,特定され,割り当てられた共鳴.
- 最もアクセシブルな残留物は,ヘリックスGの顕著な例外を除いて,膜インターフェイスにあります.
- ヘリックスGは,Lys231と保存された極性残留物を含んでおり,H/D交換が顕著であり,溶媒のアクセシビリティを示しています.
結論:
- ヘリックスGの溶媒アクセシビリティは,一時的に露出する水性性空洞の仮説を支持する.
- 潜在的にヘリックスGで覆われているこの空洞は,陽子伝導経路の一部かもしれない.
- NMRデータは,プロテオロドプシンにおける陽子ポンプの構造的基礎についての洞察を提供します.
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