Rokutan K, Thomas J A, Johnston R B
Department of Pediatrics, University of Pennsylvania, Philadelphia 19104.
J Immunol. 1991 Jul 1;147(1):260-4.
Addition of chemical oxidants to cells in culture has been shown to induce binding of low-molecular-weight thiols to reactive sulfhydryls on proteins in a process termed S-thiolation. We found that stimulation of the respiratory burst in mouse macrophages, with release of O2-, resulted in S-thiolation of several proteins, most prominently three with molecular weights of 74, 33, and 22 kDa. One protein (28 kDa) was S-thiolated without addition of an exogenous stimulus. Exposure of cells to concentrations of hydrogen peroxide like those released in the respiratory burst induced S-thiolation of these same proteins. S-thiolation and release of O2- began at approximately the same time. Stimulation of LPS-elicited macrophages induced prominent S-thiolation of three different proteins (38, 30, and 21 kDa). Under the conditions of these experiments, there was no detectable increase in glutathione disulfide and a negligible decrease in glutathione, which suggests that S-thiolation can occur without significant perturbation of the glutathione peroxidase/reductase cycle. S-thiolation of proteins could help protect the macrophage against the autoxidative damage associated with the respiratory burst. Modification of specific proteins by S-thiolation might serve to modulate cellular metabolic events.
在培养细胞中添加化学氧化剂已被证明可诱导低分子量硫醇与蛋白质上的反应性巯基结合，这一过程称为S-硫醇化。我们发现，刺激小鼠巨噬细胞的呼吸爆发并释放超氧阴离子（O₂⁻）会导致几种蛋白质发生S-硫醇化，最显著的是三种分子量分别为74 kDa、33 kDa和22 kDa的蛋白质。有一种蛋白质（28 kDa）在未添加外源刺激的情况下就发生了S-硫醇化。将细胞暴露于呼吸爆发过程中释放的过氧化氢浓度下，会诱导这些相同蛋白质发生S-硫醇化。S-硫醇化和超氧阴离子的释放大约同时开始。刺激脂多糖诱导的巨噬细胞会导致三种不同蛋白质（38 kDa、30 kDa和21 kDa）发生显著的S-硫醇化。在这些实验条件下，谷胱甘肽二硫化物没有可检测到的增加，谷胱甘肽有可忽略不计的减少，这表明S-硫醇化可以在不显著干扰谷胱甘肽过氧化物酶/还原酶循环的情况下发生。蛋白质的S-硫醇化可能有助于保护巨噬细胞免受与呼吸爆发相关的自氧化损伤。通过S-硫醇化对特定蛋白质进行修饰可能有助于调节细胞代谢事件。
