Antioxidant reactions of dihydrolipoic acid and lipoamide with triplet duroquinone

被引：19

作者：

Bisby, RH ^{[1
]}

Parker, AW

机构：

[1] Univ Salford, Dept Biol Sci, Salford M5 4WT, Lancs, England

[2] Rutherford Appleton Lab, Lasers Sci Facil, Didcot OX11 0QX, Oxon, England

来源：

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS | 1998年 / 244卷 / 01期

基金：

英国生物技术与生命科学研究理事会;

关键词：

lipoamide; dihydrolipoate; radical; oxidation; Raman;

D O I：

10.1006/bbrc.1998.8245

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

The oxidation of the antioxidants dihydrolipoate and lipoamide by triplet duroquinone ((3)DQ) has been studied by laser flash photolysis and time-resolved resonance Raman (TR3) spectroscopy. Reaction of (3)DQ with lipoamide by electron transfer [k(H2O)/k(D2O similar to 1] was more rapid than with dihydrolipoate, in which a proton is also involved [k(H2O)/k(D2O similar to 2]. For dihydrolipoate at neutral pH the undeprotonated form was the major reactive species with k similar to 10(9) dm(3) mol(-1) s(-1). At higher pH values the reaction of ionised (thiolate) forms was observed with k greater than or equal to 4 x 10(9) dm(3) mol(-1) s(-1). The electron transfer mechanism of reaction between 3DQ and lipoamide was confirmed by TR3 spectra in which formation of the durosemiquinone radical anion and lipoamide disulfide radical cation (RSS+.) was observed. (C) 1998 Academic Press.

引用

页码：263 / 267

页数：5

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