Allelic variants of glutathione S-transferase P1-1 differentially mediate the peroxidase function of peroxiredoxin VI and alter membrane lipid peroxidation.
Allelic variants of glutathione S-transferase P1-1 differentially mediate the peroxidase function of peroxiredoxin VI and alter membrane lipid peroxidation.
复制标题
DOI：
10.1016/j.freeradbiomed.2012.10.556
复制
发表时间：
2013-01
影响因子：
7.4
通讯作者：
Townsend, D. M.
中科院分区：
文献类型：
--
作者：
Manevich, Y.;Hutchens, S.;Tew, K. D.;Townsend, D. M.
关键词：
双功能抗氧化酶过氧化物酶VI （Prdx6）解毒脂质过氧化物，特别是在生物膜上，其过氧化物酶功能是由谷胱甘肽s转移酶（GSTP）激活的。GSTP基因在人类中是多态性的，有野生型GSTP1-1A （Ile105, Ala114）和三个变体：GSTP1-1B (Ile105Val, Ala114), GSTP1-1C （Ile105Val, Ala114Val）和GSTP1-1D （Ile105, Ala114Val）。本研究的重点是确定这些多态性对Prdx6过氧化物酶功能的影响。通过细胞外生成oh自由基和荧光（DPPP染料）检测，我们发现转染了催化失活的GSTP1-1和GSTP1-1B或GSTP1-1D的Y7F突变体的MCF-7细胞膜上的脂质过氧化快速（~300 s）开始。然而，在表达GSTP1-1A或GSTP1-1C的细胞中未检测到这种效应。DPPP标记的MCF-7细胞成像显示荧光定位于质膜，但在表达GSTP1-1A和GSTP1-1C的细胞中，荧光强度明显减弱。此外，在GSTP1-1A的Y7F突变体中，表达GSTP1-1B和GST1-1D的细胞*OH生成（36 h后）导致质膜通透性相关的细胞死亡，而表达GSTP1-1A和GSTP1-1C的细胞存活率明显提高。我们使用FRET分析来测量纯化的GSTP1-1等位变异蛋白与纯化的重组Prdx6的体外结合。Prdx6与gsh负载的GSTP1-1s结合的亲和力反映了它们观察到的过氧化物酶活性（使用磷脂过氧化氢作为底物）：GSTP1-1A > GSTP1-1C （KD= 51.0 vs 57.0nM）或与失活相对应：GSTP1-1B (GSTP1-1D) （KD= 101.0 (94.0)nM）。对GSTP1-1 - Prdx6异源二聚体的“in - silicon”建模显示，GSTP1-1多态性位点（Ile105和Ala114）靠近结合界面。因此，GSTP1-1多态性变异调节Prdx6过氧化物酶功能的有效性存在等级关系，这一特征可能影响人类对氧化应激的易感性。
The dual-functioning antioxidant enzyme peroxiredoxin VI (Prdx6) detoxifies lipid peroxides particularly in biological membranes and its peroxidase function is activated by glutathione S-transferase pi (GSTP). The GSTP gene is polymorphic in humans, with the wild type GSTP1-1A (Ile105, Ala114) and three variants: GSTP1-1B (Ile105Val, Ala114), GSTP1-1C (Ile105Val, Ala114Val) and GSTP1-1D (Ile105, Ala114Val). The focus of the present study is to determine the influence of these polymorphisms on Prdx6 peroxidase function. Using extracellular generation of OH-radicals and fluorescent (DPPP dye) detection, we found a fast (~300 s) onset of lipid peroxidation in membranes of MCF-7 cells transfected with a catalytically inactive Y7F mutant of GSTP1-1 and either GSTP1-1B or GSTP1-1D. However, this effect was not detected in cells expressing either GSTP1-1A or GSTP1-1C. Imaging of DPPP labeled MCF-7 cells showed fluorescence localized in the plasma membrane, but intensity was substantially diminished in the GSTP1-1A and GSTP1-1C expressing cells. Moreover, in the Y7F mutant of GSTP1-1A, GSTP1-1B and GST1-1D expressing cells *OH generation resulted (after 36 h) in plasma membrane-permeability-related cell death, while GSTP1-1A and GSTP1-1C expressing cells had significantly better survival. We used FRET analyses to measure in vitro binding of purified GSTP1-1 allelic variant proteins to purified recombinant Prdx6. The affinities for Prdx6 binding to GSH-loaded GSTP1-1s mirrored their observed peroxidase activities (using phospholipid hydroperoxide as a substrate): GSTP1-1A > GSTP1-1C (KD= 51.0 vs 57.0nM) or corresponded with inactivation: GSTP1-1B (GSTP1-1D) (KD= 101.0 (94.0)nM, respectively). “In-silico” modeling of the GSTP1-1 – Prdx6 heterodimer revealed that the sites of GSTP1-1 polymorphism (Ile105 and Ala114) are in close proximity to the binding interface. Thus, there is a hierarchy of effectiveness for polymorphic variants of GSTP1-1 to regulate Prdx6 peroxidase function, a feature that may influence human population susceptibilities to oxidant stress.
登录
查看更多内容
影响因子：
5.7
作者：
Ho, Jin-Nyoung;Lee, Seung Bum;Um, Hong-Duck
通讯作者：
Um, Hong-Duck
影响因子：
4.1
作者：
Wu, Yongzheng;Feinstein, Sheldon I.;Fisher, Aron B.
通讯作者：
Fisher, Aron B.
影响因子：
3.6
作者：
Townsend, DM;Findlay, VJ;Tew, KD
通讯作者：
Tew, KD
影响因子：
3.4
作者：
Li, Da-Qiang;Wang, Lei;Shao, Zhi-Min
通讯作者：
Shao, Zhi-Min
谷胱甘肽 s-转移酶 pi 1 的变体表现出不同的酶活性和重金属抑制作用。
影响因子：
3.2
作者：
Goodrich, Jaclyn M.;Basu, Niladri
通讯作者：
Basu, Niladri