Proteomics Research Group, Department of Biochemistry, University College Cork, Ireland.
J Proteome Res. 2010 May 7;9(5):2678-87. doi: 10.1021/pr1001719.
Protein sulfenic acids have been proposed as potential biochemical switches for redox signaling. This post-translational modification (PTM) is readily reversible, in contrast to some other types of oxidative PTM. Enhanced oxidative stress has been reported as a feature of hypertension, and renal function has been implicated in the development and progression of the disease in animal models such as the spontaneously hypertensive rat (SHR). However, reactive oxygen species (ROS) are also signaling molecules and may play a role in vascular function. To investigate protein sulfenation under hypertensive conditions, we examined protein extracts of SHR kidney medulla in comparison to medulla from normotensive Wistar rats. Total free thiol content of the SHR medulla was significantly lower than that of Wistar medulla, indicating enhanced oxidation of sulfhydryls. Protein sulfenation was also significantly greater in the medulla of hypertensive animals. Thioredoxin reductase activity was also reduced in SHR medulla and this may account, in part, for enhanced protein sulfenation. Purification of sulfenated proteins from SHR medulla revealed several proteins involved in processes such as metabolism, antioxidant defense, and regulation of nitric oxide synthase. Enhanced sulfenation may represent perturbed redox signaling in SHR medulla, or simply enhanced ROS generation.
蛋白质亚磺酸已被提议作为氧化还原信号的潜在生化开关。与其他一些类型的氧化 PTM 相比，这种翻译后修饰 (PTM) 很容易逆转。据报道，增强的氧化应激是高血压的一个特征，并且肾功能已被牵连到动物模型（如自发性高血压大鼠（SHR））中疾病的发展和进展。然而，活性氧 (ROS) 也是信号分子，可能在血管功能中发挥作用。为了研究高血压条件下的蛋白质亚磺化，我们比较了 SHR 肾脏髓质的蛋白质提取物与正常血压 Wistar 大鼠的髓质。SHR 髓质的总游离巯基含量明显低于 Wistar 髓质，表明巯基的氧化增强。高血压动物髓质中的蛋白质亚磺化也明显增加。SHR 髓质中的硫氧还蛋白还原酶活性也降低，这可能部分解释了蛋白质亚磺化的增强。从 SHR 髓质中纯化的亚磺化蛋白质揭示了几种涉及代谢、抗氧化防御和一氧化氮合酶调节等过程的蛋白质。增强的亚磺化可能代表 SHR 髓质中氧化还原信号的紊乱，或者仅仅是增强的 ROS 生成。
