丙酮酸和过氧化氢的反应速率：在生物条件下评估丙酮酸的抗氧化能力。,Scientific Reports

当前位置： X-MOL 学术 › Sci. Rep. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

丙酮酸和过氧化氢的反应速率：在生物条件下评估丙酮酸的抗氧化能力。
Scientific Reports ( IF 3.8 ) Pub Date : 2019-12-20 , DOI: 10.1038/s41598-019-55951-9
Victoria A Guarino ₁ , William M Oldham ₁ , Joseph Loscalzo ₁ , Ying-Yi Zhang ₁

Affiliation

丙酮酸是一种关键的葡萄糖代谢产物，是一种与过氧化氢（H2O2）反应的α-酮酸。其药理学前体丙酮酸乙酯在各种疾病的动物模型中均显示出抗炎/抗组织损伤的作用，但在一项多中心临床试验中失败了。由于啮齿动物而非人类可以在血浆中将丙酮酸乙酯转化为丙酮酸，因此细胞外丙酮酸的这种额外来源可能导致了物种之间的差异。为了检验这种可能性，我们研究了生物学条件下反应的动力学并确定了二级速率常数k为2.360±0.198 M-1 s-1。然后，我们计算了丙酮酸消除H2O2所需的时间。结果表明，在丙酮酸的平均细胞内浓度（150 µM）下，在正常至病理浓度（0.01-50 µM）下消除95％H2O2需要141-185分钟（2.4-3小时）。使用1,000 µM丙酮酸（只能在细胞外或细胞培养基中存在的浓度），在5-200 µM处95％的H2O2消除需要21-25分钟。我们得出的结论是，内源性浓度受代谢控制的细胞内丙酮酸或其他α-酮酸在H2O2清除中几乎没有作用。然而，考虑到在该空间中过氧化物酶的活性最小，丙酮酸增加的细胞外浓度确实具有明显的过氧化物清除作用。我们得出的结论是，内源性浓度受代谢控制的细胞内丙酮酸或其他α-酮酸在H2O2清除中几乎没有作用。然而，考虑到在该空间中过氧化物酶的活性最小，丙酮酸增加的细胞外浓度确实具有明显的过氧化物清除作用。我们得出的结论是，内源性浓度受代谢控制的细胞内丙酮酸或其他α-酮酸在H2O2清除中几乎没有作用。然而，考虑到在该空间中过氧化物酶的活性最小，丙酮酸增加的细胞外浓度确实具有明显的过氧化物清除作用。

"点击查看英文标题和摘要"

Reaction rate of pyruvate and hydrogen peroxide: assessing antioxidant capacity of pyruvate under biological conditions.

Pyruvate, a pivotal glucose metabolite, is an α-ketoacid that reacts with hydrogen peroxide (H2O2). Its pharmacological precursor, ethyl pyruvate, has shown anti-inflammatory/anti-tissue injury effects in various animal models of disease, but failed in a multicenter clinical trial. Since rodents, but not humans, can convert ethyl pyruvate to pyruvate in blood plasma, this additional source of extracellular pyruvate may have contributed to the discrepancy between the species. To examine this possibility, we investigated the kinetics of the reaction under biological conditions and determined the second order rate constant k as 2.360 ± 0.198 M-1 s-1. We then calculated the time required for H2O2 elimination by pyruvate. The results show that, with an average intracellular concentration of pyruvate (150 µM), elimination of 95% H2O2 at normal to pathological concentrations (0.01-50 µM) requires 141-185 min (2.4-3 hour). With 1,000 µM pyruvate, a concentration that can only exist extracellularly or in cell culture media, 95% elimination of H2O2 at 5-200 µM requires 21-25 min. We conclude that intracellular pyruvate, or other α-ketoacids, whose endogenous concentration is controlled by metabolism, have little role in H2O2 clearance. An increased extracellular concentration of pyruvate, however, does have remarkable peroxide scavenging effects, considering minimal peroxidase activity in this space.

更新日期：2019-12-20

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南