Turell Lucía, Radi Rafael, Alvarez Beatriz
Laboratorio de Enzimología, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay; Laboratorio de Fisicoquímica Biológica, Facultad de Ciencias, Universidad de la República, 11400 Montevideo, Uruguay; Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, 11800 Montevideo, Uruguay.
Center for Free Radical and Biomedical Research, Facultad de Medicina, Universidad de la República, 11800 Montevideo, Uruguay; Departamento de Bioquímica, Facultad de Medicina, Universidad de la República, 11800 Montevideo, Uruguay.
Free Radic Biol Med. 2013 Dec;65:244-253. doi: 10.1016/j.freeradbiomed.2013.05.050. Epub 2013 Jun 7.
The plasma compartment has particular features regarding the nature and concentration of low and high molecular weight thiols and oxidized derivatives. Plasma is relatively poor in thiol-based antioxidants; thiols are in lower concentrations than in cells and mostly oxidized. The different thiol-disulfide pairs are not in equilibrium and the steady-state concentrations of total thiols as well as reduced versus oxidized ratios are maintained by kinetic barriers, including the rates of reactions and transport processes. The single thiol of human serum albumin (HSA-SH) is the most abundant plasma thiol. It is an important target for oxidants and electrophiles due to its reactivity with a wide variety of species and its relatively high concentration. A relatively stable sulfenic (HSA-SO3H) acid can be formed in albumin exposed to oxidants. Plasma increases in mixed disulfides (HSA-SSR) or in sulfinic (HSA-SO2H) and sulfonic (HSA-SO3H) acids are associated with different pathologies and may constitute biomarkers of the antioxidant role of the albumin thiol. In this work we provide a critical review of the plasma thiol pool with a focus on human serum albumin.
血浆部分在低分子量和高分子量硫醇及其氧化衍生物的性质和浓度方面具有特定特征。血浆中基于硫醇的抗氧化剂相对较少；硫醇的浓度低于细胞中的浓度，且大多被氧化。不同的硫醇 - 二硫键对处于非平衡状态，总硫醇的稳态浓度以及还原态与氧化态的比率由动力学屏障维持，包括反应速率和转运过程。人血清白蛋白的单个硫醇（HSA - SH）是血浆中最丰富的硫醇。由于其与多种物质的反应性以及相对较高的浓度，它是氧化剂和亲电试剂的重要靶点。在暴露于氧化剂的白蛋白中可形成相对稳定的亚磺酸（HSA - SO3H）。血浆中混合二硫化物（HSA - SSR）或亚磺酸（HSA - SO2H）和磺酸（HSA - SO3H）酸的增加与不同的病理状况相关，可能构成白蛋白硫醇抗氧化作用的生物标志物。在这项工作中，我们对血浆硫醇库进行了批判性综述，重点关注人血清白蛋白。
