細菌のペロキシレドキシンによるペロキシニトリート還元酵素の活性
1Department of Microbiology and Immunology, Weill Medical College of Cornell University, New York, New York 10021, USA.
Nature
|September 23, 2000
まとめ
ペロキシレドキシンは,サルモネラ・タイフィムリウム (Salmonella typhimurium) の AhpC のように,有害なペロキシニトライトを排毒することができます. バクテリアに存在するこの酵素活動は,DNAのような細胞分子を酸化的損傷から保護します.
科学分野:
- バイオケミストリー バイオケミストリー
- 微生物学 微生物学とは
- 細胞生物学 細胞生物学
背景:
- 酸化窒素 (NO) と超酸化窒素 (O2-) は反応してペロキシニート (OONO-) を形成する.
- ペロキシニトリートは,酸化性,炎症性,変異性,および細胞毒性の可能性を持つ反応性分子です.
- ペロキシニトリットと向き合うための細胞メカニズムは,NOの生物学的効果を理解するために不可欠です.
研究 の 目的:
- 細胞がペロキシニトライトを排毒する酵素を持っているかどうかを調査する.
- ペロキシニトリトの解毒におけるペロキシレドキシンの潜在的な役割を調査する.
主な方法:
- 酵素アッセイでは,サルモネラ・タイフィミュリウム菌からのペロキシレドキシンアルキルヒドロペロキシド還元酵素サブユニットC (AhpC) を使用しています.
- ペロキシニトリートの解毒におけるAhpCの触媒的活性を試験する.
- 結果をMycobacterium tuberculosisとHelicobacter pyloriからのペロキシレドキシンと比較した.
主要な成果:
- サルモネラ・タイフィムリウムのAhpCは,ペロキシニートからニートリートに触媒的に解毒することが示されました.
- この解毒は急速に起こり,DNAのような傍観者分子の損傷を防ぐ.
- 同様のペロキシニトリート還元酵素活性が,Mycobacterium tuberculosisとHelicobacter pyloriからのペロキシレドキシンで観察されました.
結論:
- ペロキシレドキシン,特にAhpCは,ペロキシニート還元酵素活性を持っています.
- この酵素活性は,ペロキシニートによって引き起こされる損傷から細胞成分を保護するのに十分です.
- ペロキシニトリート還元酵素の活性性は,細菌系全体で広範囲にわたる解毒メカニズムである可能性があります.
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