ヒスタミン結合によるO2と銅の直接的形成

J Brannon Gary¹, Cooper Citek¹, Timothy A Brown¹

¹Department of Chemistry, Stanford University , Stanford, California 94305, United States.

Journal of the American Chemical Society

|July 29, 2016

まとめ

銅 (III) は,銅を水酸化する酵素において活性の高い酸化状態であり,三核および二核製品を形成する. 反応性の違いは,酸化力ではなく,リガンドのアクセシビリティによる.

科学分野:

生物化学
無機化学
酵素メカニズム

背景:

銅を水酸化する酵素は,銅のヒスタミンケラチンを利用して,酸化酸素を活性化します.
生成される酸化物質は,通常,銅 (II) 種であると考えられる.

研究の目的:

ヒスタミン結合銅の複合体の酸素化による銅を含む製品の直接的形成を証明する.
これらのシステムにおける銅の動力学と熱力学的活性を調査する.
三核と二核の銅酸化物種の構造と反応性の違いを探求する.

主な方法:

ヒスタミン結合銅 (I) 複合体の合成と特徴付け
低温での酸素化試験
産物形成と反応性の運動分析
スペクトル検査と構造検査

主要な成果:

酸素化ヒスタミン-銅複合体における銅 (III) 形成の直接的な証拠
低温で主たる三核Cu (II) 2Cu (III) O2と二核Cu (III) 2O2の種を特定する.
パーオキシドレベルのダイマー中間物質が,前製品バイフォーケーションを証明する.
三核複合体と二核複合体間の水素原子の反応性の大きな違い

結論:

銅 (III) は,これらの銅-酸素系において,運動的および熱力学的に利用可能な酸化状態である.
ヒスタミンリガンドの構造は三核と二核の銅酸化物の分布に影響する.
反応性の差異は,ブリッジング酸化リガンドのアクセシビリティに起因し,固有の酸化強さの変動ではない.

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