Side-chain oxidative damage to cysteine on a glassy carbon electrode.
In this paper, oxidative damage to the cysteine (CySH) side-chain on a glassy carbon electrode (GCE) was investigated. Voltammetric studies show that there are three anodic peaks for the oxidation of CySH, which arise from (1) the oxidation of the -SH side-chain, forming cystine (0.71 V, vs. SCE) and (2) CySO( x )H, x = 2, 3 (0.98 V vs. SCE), and (3) the oxidation of the amino acid carboxyl group (around 1.51 V vs. SCE). The influence of dissolved oxygen, pH, scan rate, scan time, temperature and CySH concentration were investigated and the oxidative mechanism proposed. The peaks near 0.71 and 0.98 V are the promising candidates for measuring the oxidation of CySH on the GCE. This paper provides a new strategy for researching oxidative damage of amino acids, sulfur-containing peptides and proteins.
Zong
Wansong
W
School of Environmental Science and Engineering, Shandong University, 27# Shanda South Road, 250100, Jinan, People's Republic of China.
Liu
Rutao
R
Zhao
Lingzi
L
Tian
Yanmin
Y
Yuan
Dong
D
Gao
Canzhu
C
D002244:Carbon / Q000737:chemistry; D003545:Cysteine / Q000737:chemistry* / Q000378:metabolism; D004566:Electrodes; D005898:Glass / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry* / Q000378:metabolism; D013696:Temperature; D017186:Titrimetry
D002244:Carbon; D003545:Cysteine; D010100:Oxygen