Tamura Mayumi, Saito Masanori, Yamamoto Kaori, Takeuchi Tomoharu, Ohtake Kazuo, Tateno Hiroaki, Hirabayashi Jun, Kobayashi Jun, Arata Yoichiro
Department of Biochemistry, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Division of Pathophysiology, Department of Clinical Dietetics and Human Nutrition, Faculty of Pharmaceutical Sciences, Josai University, Saitama 350-0295, Japan.
Biochem Biophys Res Commun. 2015 Feb 20;457(4):712-7. doi: 10.1016/j.bbrc.2015.01.055. Epub 2015 Jan 22.
Galectins are a group of animal lectins characterized by their specificity for β-galactosides. Galectin-2 (Gal-2) is predominantly expressed in the gastrointestinal tract. A proteomic analysis identified Gal-2 as a protein that was S-nitrosylated when mouse gastric mucosal lysates were reacted with S-nitrosoglutathione, a physiologically relevant S-nitrosylating agent. In the present study, recombinant mouse (m)Gal-2 was S-nitrosylated using nitrosocysteine (CysNO), which had no effect on the sugar-binding specificity and dimerization capacity of the protein. On the other hand, mGal-2 oxidation by H2O2 resulted in the loss of sugar-binding ability, while S-nitrosylation prevented H2O2-inducted inactivation, presumably by protecting the Cys residue(s) in the protein. These results suggest that S-nitrosylation by nitric oxides protect Gal-2 from oxidative stress in the gastrointestinal tract.
半乳糖凝集素是一类动物凝集素，其特点是对β-半乳糖苷具有特异性。半乳糖凝集素-2（Gal-2）主要在胃肠道表达。一项蛋白质组学分析确定，当小鼠胃黏膜裂解物与生理相关的亚硝基化剂亚硝基谷胱甘肽反应时，Gal-2是一种发生S-亚硝基化的蛋白质。在本研究中，重组小鼠（m）Gal-2使用亚硝基半胱氨酸（CysNO）进行S-亚硝基化，这对该蛋白质的糖结合特异性和二聚化能力没有影响。另一方面，H2O2对mGal-2的氧化导致糖结合能力丧失，而S-亚硝基化可防止H2O2诱导的失活，推测这是通过保护蛋白质中的半胱氨酸残基实现的。这些结果表明，一氧化氮介导的S-亚硝基化可保护Gal-2免受胃肠道中的氧化应激。
