期刊
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
卷 133, 期 49, 页码 19823-19831出版社
AMER CHEMICAL SOC
DOI: 10.1021/ja206980q
关键词
-
资金
- Swiss National Science Foundation [200020-127142]
- NSFC [20925517]
- EPFL
- Swiss National Science Foundation (SNF) [200020_127142] Funding Source: Swiss National Science Foundation (SNF)
Tyrosine nitration, often observed during neurodegenerative disorders under nitrative stress, is usually considered to be induced chemically either by nitric oxide and oxygen forming nitrogen dioxide or by the decomposition of peroxynitrite. It can also be induced enzymatically by peroxidases or superoxide dismutases in the presence of both hydrogen peroxide and nitrite forming nitrogen dioxide and/or peroxynitrite. In this study, the role of cupric ions for catalyzing tyrosine nitration in the presence of hydrogen peroxide and nitrite, by a chemical mechanism rather similar to enzymatic pathways where nitrite is oxidized to form nitrogen dioxide, was investigated by development of a microreactor also capable of acting as an emitter for electrospray ionization mass spectrometry analysis. Indeed, cupric ions and peptide-cupric ion complexes are found to be excellent Fenton catalysts, even better than Fe(III) or heme, for the formation of (OH)-O-center dot radicals and/or copper(II)-bound (OH)-O-center dot radicals from hydrogen peroxide. These radicals are efficiently scavenged by nitrite anions to form (NO2)-N-center dot and by tyrosine to form tyrosine radicals, leading to tyrosine nitration in polypeptides. We also show that cupric ions can catalyze tyrosine nitration from nitric oxide, oxygen, and hydrogen peroxide as the formation of tyrosine radicals is increased in the presence of diffusible and/or copper(II) bound hydroxyl radicals. This study shows that copper has a polyvalent role in the processes of tyrosine nitration.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据