Study on the mechanism of nitrosothiol formation in biological systems

生物系统中亚硝基硫醇形成机制的研究

基本信息

批准号：
12670142
负责人：
MIYAMOTO Yoichi
金额：
$ 2.24万
依托单位：
Showa University (2002)Kumamoto University (2000-2001)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2002
项目状态：
已结题

项目摘要

Nitric oxide (NO) exhibits multiple biological actions through formation of various intermediates derived from NO. Among them, we found that nitrosothiols (RSNOs), adducts of SH moiety of biological compounds and NO, could be formed efficiently via one-electron oxidation of NO catalyzed by ceruloplasmin, a major copper-containing protein in plasma. In addition, we identified S-oxiso-nitrosoglutathione [GS(O)NO] as a reaction product of glutathione and peroxynitrite (ONOO^-), an adduct of NO and superoxide. Furthermore, GS(O)NO activated matrix metalloproteinases (MMPs) through formation of dithiothreitol-resistant S-glutathionyl MMPs, indicating that ONOO^- exerts its tissue destructive effects via formation of S-oxo-nitrosothiols as well as direct nitration or oxidation of biological molecules. In the latter part of this project, we investigated the biological significance of nitrosative and nitrative stresses in inflammatory disorders including rheumatoid arthritis (RA), where NO production is accelerated. We could detect the expression of ceruloplasmin in chondrocytes, suggests the possible formation of nitrosothiols in the inflammatory foci of RA. On the other hand, it is reported that α_1-protease inhibitor (α_1PI) level in joint is increased in RA patients. As we reported earlier, α1PI is readily S-niotrosylated by NO and S-nitrosylated α1PI shows tissue protective effects in vitro and in vivo. In this study we studied nitrosylation of methionine-oxidized α1PI [α_1PI-Met(O)] and the biological activities of this reaction products, because RA joints are thought to be under highly oxidative conditions. The efficacy of S-nitrosylation of α_1PI-Met(O) was around 80% of that of α1PI. Interestingly, antibacterial activity of S- nitrosylated α1PI-Met(O) in vitro was 100 times more potent than that of S-nitrosylated α_1PI. The further study will be performed to clarify the pathophysiological roles of S-nitrosylated α_1PI-Met(O).

一氧化氮（NO）通过形成从NO的各种中间体形成。其中，我们发现硝基硫醇（RSNOS）可以通过ceruroplasmin（一种主要的含铜蛋白质蛋白质的ceruroplasmin ceruroplasmin ceruroplasmin ceruroplasmin ceruroplasmin催化）的单电子氧化物有效地形成。此外，我们确定了s-氧基硝基谷胱甘肽[GS（O）NO]为谷胱甘肽和过氧硝酸盐（Onoo^ - ）的反应产物，NO和超氧化物的加合物。此外，GS（O）通过形成抗二硫代硫代醇的S-谷硫二硫代MMP的GS（O）无激活的基质金属蛋白酶（MMP），表明Onoo^ - 通过形成S-Oxo-硝基硫醇或氧化二核的S-氧基二硝基化或氧化二氮，从而产生其组织破坏性效应。在该项目的后半部分，我们研究了包括类风湿关节炎（RA）在内的硝酸和硝酸胁迫的生物学意义，该炎症性疾病（RA）没有加速产生。我们可以检测在软骨细胞中cer胞素蛋白的表达，这表明RA炎症灶中可能形成硝基硫醇。另一方面，据报道，RA患者的关节中α_1-蛋白酶抑制剂（α_1PI）水平有所增加。正如我们之前报道的那样，α1Pi很容易被NO和S-硝基化的α1PI拟南芥基因，在体外和体内显示了组织受保护的效应。在这项研究中，我们研究了蛋氨酸氧化的α1Pi[α_1pi-met（O）]和该反应产物的生物学活性的硝基化，因为RA关节被认为是高度氧化的条件。 α_1PI-MET（O）的S-亚硝基化效率约为α1Pi的效率。有趣的是，体外S-亚硝基化α1PI-MET（O）的抗菌活性的潜力是S-硝基化α_1PI的抗菌活性。将进行进一步的研究，以阐明S-硝基化α_1PI-MET（O）的病理生理作用。