Previous studies have indicated that the main molecular characteristic of aging is the progressive accumulation of oxidative damages in cellular macromolecules. Proteins are one of the main molecular targets of age-related oxidative stress, which have been observed during aging process in cellular systems. Reactive oxygen species (ROS) can lead to oxidation of amino acid side chains, formation of protein-protein cross-linkages, and oxidation of the peptide backbones. In the present study, we report the age-dependent oxidative alterations in biomarkers of plasma protein oxidation: protein carbonyls (PCO), advanced oxidation protein products (AOPPs) and plasma total thiol groups (T-SH) in the Indian population and also correlate these parameters with total plasma antioxidant potential. We show an age dependent decrease in T-SH levels and increase in PCO and AOPPs level. The alterations in the levels of these parameters correlated significantly with the total antioxidant capacity of the plasma. The levels of oxidized proteins in plasma provide an excellent biomarker of oxidative stress due to the relative long half-life of such oxidized proteins.

中文翻译：

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血浆蛋白氧化及其与人类衰老过程中抗氧化潜力的相关性。

以往的研究表明，衰老的主要分子特征是细胞大分子氧化损伤的逐渐积累。蛋白质是与年龄相关的氧化应激的主要分子靶标之一，在细胞系统的衰老过程中已经观察到。活性氧 (ROS) 可导致氨基酸侧链氧化、蛋白质-蛋白质交联的形成以及肽主链的氧化。在本研究中，我们报告了印度人群中血浆蛋白氧化生物标志物的年龄依赖性氧化改变：蛋白羰基化合物 (PCO)、高级氧化蛋白产物 (AOPPs) 和血浆总硫醇基团 (T-SH)，并且还与这些参数与总血浆抗氧化潜力有关。我们显示 T-SH 水平随年龄增加而降低，PCO 和 AOPPs 水平增加。这些参数水平的变化与血浆的总抗氧化能力显着相关。由于这种氧化蛋白的半衰期相对较长，血浆中氧化蛋白的水平提供了极好的氧化应激生物标志物。