文献类型：期刊文献

英文题名：Quinopeptide formation associated with the disruptive effect of epigallocatechin-gallate on lysozyme fibrils

作者：Cao, Na Zhang, Yu-Jie Feng, Shuang Zeng, Cheng-Ming

第一作者：Cao, Na

通信作者：Zeng, CM[1]

机构：[1]Shaanxi Normal Univ, Sch Chem & Chem Engn, Key Lab Analyt Chem Life Sci Shaanxi Prov, Xian 710119, Peoples R China;[2]Guizhou Inst Technol, Sch Chem Engn, Guiyang 550003, Peoples R China

第一机构：Shaanxi Normal Univ, Sch Chem & Chem Engn, Key Lab Analyt Chem Life Sci Shaanxi Prov, Xian 710119, Peoples R China

通信机构：corresponding author), Shaanxi Normal Univ, Sch Chem & Chem Engn, Key Lab Analyt Chem Life Sci Shaanxi Prov, Xian 710119, Peoples R China.

年份：2015

卷号：78

起止页码：389-395

外文期刊名：INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES

收录：;Scopus(收录号：2-s2.0-84929460967);WOS:【SCI-EXPANDED(收录号:WOS:000356195400052)】；

基金：This work was supported by the Fundamental Research Funds for the Central Universities (GK20133001). We thank Miss Gai-Tao Li for her invaluable assistance in performing NBT assays.

语种：英文

外文关键词：Epigallocatechin-3-gallate; Amyloid fibrils; Quinopeptides

摘要：Numerous studies demonstrate that natural polyphenols can inhibit amyloid formation and disrupt preformed amyloid fibrils. In the present study, the fibril-disruptive effects of epigallocatechin-3-gallate (EGCG) were examined using lysozyme as a model protein. The results indicated that EGCG dose dependently inhibited lysozyme fibrillation and modified the peptide chains with quinonoid moieties under acidic conditions, as measured by ThT fluorescence, transmission electron microscopy, and an NBT-staining assay. Moreover, EGCG transformed the preformed lysozyme fibrils to amorphous aggregates through quinopeptide formation. The thiol blocker, N-ethylmaleimide, inhibited the disruptive effect of EGCG on preformed fibrils, suggesting that thiol groups are the binding sites for EGCG. We propose that the formation of quinone intermediates via oxidation and subsequent binding to lysozyme chains are the main processes driving the inhibition of amyloid formation and disruption of preformed fibrils by EGCG. The information presented in this study may provide fresh insight into the link between the antioxidant capacity and anti-amyloid activity of polyphenols. (C) 2015 Elsevier B.V. All rights reserved.