Involvement of phospholipid, biomembrane integrity, and NO peroxidase activity in the NO catabolism by cytochrome c oxidase

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• 作者：Chen ; Yeong-Renn ; Chen ; Chwen-Lih ; Liu ; Xiaoping ; He ; Guanglong ; Zweier ; Jay L.
• 关键词：CcO ; NO ; SMP ; Phospholipid ; Membrane integrity ; H₂O₂ ; Peroxidase ; Protein radical
• 刊名：Archives of Biochemistry and Biophysics
• 出版年：2005
• 出版时间：July 15, 2005
• 年：2005
• 卷：439
• 期：2
• 页码：200-210
• 全文大小：644 K

文摘

The physiological regulation of mitochondrial respiration by NO has been reported to result from the reversible binding of NO to the two-electron reduced binuclear center l1"">l1&_user=10&_cdi=6701&_rdoc=7&_handle=V-WA-A-W-AA-MsSAYZW-UUW-U-AAWCVUBCWY-AAWWEYVBWY-WCDWAVDUA-AA-U&_acct=C000050221&_version=1&_userid=10&md5=8f12eff3d7c156705dc4a747085a3dbd"">lt=""Click to view the MathML source"" align=""absbottom"" border=""0"" height=21 width=88> of cytochrome c oxidase (CcO). Although the role of CcO and its derived catalytic intermediates in the catabolism of NO has been documented, little has been established for the enzyme in its fully oxidized state l2"">l2&_user=10&_cdi=6701&_rdoc=7&_handle=V-WA-A-W-AA-MsSAYZW-UUW-U-AAWCVUBCWY-AAWWEYVBWY-WCDWAVDUA-AA-U&_acct=C000050221&_version=1&_userid=10&md5=b5df41267c0ec5d6f3f00b5082f9f99b"">lt=""Click to view the MathML source"" align=""absbottom"" border=""0"" height=21 width=88>. We report: (1) CcO, in its fully oxidized state, represents the major component of the mitochondrial electron transport chain for NO consumption as controlled by the binding of NO to its binuclear center. Phospholipid enhances NO consumption by fully oxidized CcO, whereas the consumption of NO is slowed down by membrane structure and membrane potential when CcO is embedded in the phospholipid bilayer. (2) In the presence of H₂O₂, CcO was shown to serve as a mitochondria-derived NO peroxidase. A CcO-derived protein radical intermediate was induced and involved in the modulation of NO catabolism.