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ホーレンラディッシュの根から酸化および還元されたステラシアニンの結晶構造
Michael Koch1, Milko Velarde, Mark D Harrison
1Abteilung Strukturforschung, Max-Planck-Institut für Biochemie, Am Klopferspitz 18, D-82152 Martinsried, Germany.
Journal of the American Chemical Society
|January 6, 2005
まとめ
植物コプレドキシンであるウメシアニン (UMC) は,結晶構造が決定されています. そのユニークな表面の特徴と活性部位は,タンパク質間電子伝送における役割を示唆しています.
科学分野:
- バイオケミストリー バイオケミストリー
- 構造生物学 構造生物学とは
- タンパク質科学 タンパク質科学
背景:
- ウメシアニン (UMC) は,フィトシアニンのステラシアニン亜種からなる1型銅タンパク質です.
- フィトシアニンは,電子移転に関与する植物クプレドキシンの一般的な家族です.
研究 の 目的:
- 酸化 (Cu(II)) と還元 (Cu(I)) の結晶構造を決定するために,ウメシアニン.
- 電子移転におけるウメシアニンの機能の構造的基礎を解明する.
主な方法:
- X線結晶学を用いて,高解像度 (1.9と1.8A) でCu(II) とCu(I) UMCの構造を決定した.
- 酸化形態と還元形態の活性部位と表面特性の比較分析.
主要な成果:
- UMCの全体的な折り畳みは,他のフィトシアニンと似ています.
- 活性部位は,Cu(II) の歪んだ四面体幾何学とCu(I) の三角ピラミッド形幾何学を特徴としています.
- UMCは活性部位の近くには水嫌性の斑点がなく,表面には大きな酸性斑点があり,他のクプレドキシンと区別されています.
結論:
- 活性部位では,リドックス変化の際に限られた構造変化が発生し,軸性メットリガンドを持つ1型銅部位に似ています.
- ユニークな表面の特徴と活性部位構造は,タンパク質間電子移転におけるウメシアニンの役割を示唆しています.
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