Structural characteristics of green tea catechins for formation of protein carbonyl in human serum albumin
Structural characteristics of green tea catechins for formation of protein carbonyl in human serum albumin
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DOI：
10.1016/j.bmc.2010.06.021
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发表时间：
2010-07-15
影响因子：
3.5
通讯作者：
Nakayama, Tsutomu
中科院分区：
文献类型：
--
作者：
Ishii, Takeshi;Mori, Taiki;Nakayama, Tsutomu
儿茶素是在绿色茶叶中发现的多酚类抗氧化剂。最近的研究报道，各种多酚化合物，包括儿茶素，通过其促氧化作用引起蛋白质中的蛋白质羰基形成。在这项研究中，我们评估的蛋白质羰基形成的人血清白蛋白（HSA）的儿茶素和探讨儿茶素的化学结构之间的关系，其促氧化性能。为了评估HSA中蛋白质羰基的形成，将HSA与四种单独的儿茶素在生理条件下孵育以产生生物素-LC-酰肼标记的蛋白质羰基。使用蛋白质印迹法的儿茶素的比较表明，在HSA中的蛋白质羰基的形成是较高的邻苯三酚型儿茶素比相应的儿茶酚型儿茶素。此外，还发现具有没食子酰基的儿茶素的蛋白质羰基的形成高于相应的缺乏没食子酰基的儿茶素。使用甲基化儿茶素和酚酸证实了在B-环和没食子酰基中的连苯三酚结构基序的重要性。这些结果表明，茶儿茶素在HSA中形成蛋白质羰基的最重要的结构元素是B环中的邻苯三酚结构基序，其次是没食子酰基。茶儿茶素的氧化稳定性和与蛋白质的结合亲和力负责蛋白质羰基的形成，因此每种儿茶素的这些性质的差异可能有助于其生物活性的大小。(C)2010爱思唯尔有限公司版权所有。
Catechins are polyphenolic antioxidants found in green tea leaves. Recent studies have reported that various polyphenolic compounds, including catechins, cause protein carbonyl formation in proteins via their pro-oxidant actions. In this study, we evaluate the formation of protein carbonyl in human serum albumin (HSA) by tea catechins and investigate the relationship between catechin chemical structure and its pro-oxidant property. To assess the formation of protein carbonyl in HSA, HSA was incubated with four individual catechins under physiological conditions to generate biotin-LC-hydrazide labeled protein carbonyls. Comparison of catechins using Western blotting revealed that the formation of protein carbonyl in HSA was higher for pyrogallol-type catechins than the corresponding catechol-type catechins. In addition, the formation of protein carbonyl was also found to be higher for the catechins having a galloyl group than the corresponding catechins lacking a galloyl group. The importance of the pyrogallol structural motif in the B-ring and the galloyl group was confirmed using methylated catechins and phenolic acids. These results indicate that the most important structural element contributing to the formation of protein carbonyl in HSA by tea catechins is the pyrogallol structural motif in the B-ring, followed by the galloyl group. The oxidation stability and binding affinity of tea catechins with proteins are responsible for the formation of protein carbonyl, and consequently the difference in these properties of each catechin may contribute to the magnitude of their biological activities. (C) 2010 Elsevier Ltd. All rights reserved.