Yang Xiaorong, Wu Jinzi, Jing Siqun, Forster Michael J, Yan Liang-Jun
1Department of Pharmaceutical Sciences, UNT System College of Pharmacy, University of North Texas Health Science Center, Fort Worth, TX 76107 USA.
2Department of Physiology, National Key Disciplines, Key Laboratory for Cellular Physiology of Ministry of Education, Shanxi Medical University, Taiyuan, 030001 China.
Biophys Rep. 2018;4(2):104-113. doi: 10.1007/s41048-018-0053-3. Epub 2018 Apr 19.
There is accumulating evidence that cysteine sulfenation (cys-SOH) in proteins plays an important role in cellular response to oxidative stress. The purpose of the present study was to identify mitochondrial proteins that undergo changes in cys-SOH during aging. Studies were conducted in rats when they were 5 or 30 months of age. Following blocking of free protein thiols with -ethylmaleimide, protein sulfenic acids were reduced by arsenite to free thiol groups that were subsequently labeled with biotin-maleimide. Samples were then comparatively analyzed by two-dimensional Western blots, and proteins showing changes in sulfenation were selectively identified by mass spectrometry peptide sequencing. As a result, five proteins were identified. Proteins showing an age-related decrease in sulfenation include pyruvate carboxylase and pyruvate dehydrogenase; while those showing an age-related increase in sulfenation include aconitase, mitofilin, and tubulin (α-1). Results of the present study provide a general picture of mitochondrial protein sulfenation in brain oxidative stress and implicate the involvement of protein sulfenation in overall decline of mitochondrial function during brain aging.
越来越多的证据表明，蛋白质中的半胱氨酸亚磺化（cys-SOH）在细胞对氧化应激的反应中起重要作用。本研究的目的是鉴定在衰老过程中发生cys-SOH变化的线粒体蛋白质。研究在5月龄和30月龄大鼠中进行。在用N-乙基马来酰亚胺封闭游离蛋白质巯基后，亚砷酸盐将蛋白质亚磺酸还原为游离巯基，随后用生物素-马来酰亚胺标记。然后通过二维蛋白质印迹对样品进行比较分析，并通过质谱肽测序选择性鉴定显示亚磺化变化的蛋白质。结果，鉴定出了5种蛋白质。显示亚磺化随年龄下降的蛋白质包括丙酮酸羧化酶和丙酮酸脱氢酶；而显示亚磺化随年龄增加的蛋白质包括乌头酸酶、线粒体丝状蛋白和微管蛋白（α-1）。本研究结果提供了脑氧化应激中线粒体蛋白质亚磺化的总体情况，并表明蛋白质亚磺化参与了脑衰老过程中线粒体功能的整体下降。
