人間のカルプロテクチンによる高親和性マンガンの調整は,カルシウムに依存しており,ダイマー界面で形成されるヒスティジンに富んだ部位を必要とします
Joshua A Hayden1, Megan Brunjes Brophy, Lisa S Cunden
1Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Journal of the American Chemical Society
|January 2, 2013
まとめ
カルプロテクチン (CP) は,カルシウムで強化された特定のHis (His) (4) 部位でマンガン (Mn (II)) を隔離します. このタンパク質は金属をケラートし,微生物の増殖を抑制し,特にカルシウムグラデーションに反応する.
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
- 微生物学 微生物学とは
背景:
- カルプロテクチン (Calprotectin, CP) は,中性粒子が産生する抗菌タンパク質である.
- CPは,マンガンや亜鉛のような移行金属イオンをケラートすることによって,微生物の成長を抑制します.
- CPのS100A8/S100A9ダイマーインターフェースは,異なる金属結合部位を形成します.
研究 の 目的:
- カルプロテクチン (CP) のマンガン結合特性を調査する.
- S100A8/S100A9二次元内の特定のマンガンの調整部位を特徴づけるために.
- CPの金属結合親和性と選択性を調節するカルシウムの役割を理解する.
主な方法:
- 低温電子パラマグネティック共振 (EPR) スペクトロスコーピーは,Mn (II) 結合を検出する.
- サイト・ディレクテッド・ミュータゲネシスで,重要な調整残留物を特定する.
- 亜鉛とマンガンの結合を比較する金属イオン選択性測定法.
主要な成果:
- S100A8/S100A9ダイマーインターフェースのHis(4) モチーフは,高親和性Mn(II) 結合部位である.
- 顕微鏡分析により,この場所には八面形のMn (II) 座標球があることが明らかになった.
- カルシウム結合により,Mn{\displaystyle Mn} の親和性が著しく増加し,CPはZn{\displaystyle Zn} の選択性が高くなります.
結論:
- CPは,カルシウムレベルに影響される高親和性Mn (II) 調整のためのHis (−4) サイトを使用します.
- 混合Zn:Mn:CP複合体の形成が好まれる.
- CPは,カルシウム調節された,高親和性金属ケレーターとして作用し,微生物の増殖を細胞外的に抑制します.
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