Activation of hydrogen peroxide by copper (II) complexes with some histidine-containing peptides and their SOD-like activities.
The reactivities of copper(II) complexes with histidine-containing oligopeptides towards active oxygen species such as hydrogen peroxide (H2O2) and superoxide ion (O2-) were investigated by electron spin resonance (ESR)-spin trapping and thiobarbituric acid (TBA) methods. At physiological pH values, Cu(II) complexes with oligopeptides containing histidyl residue at the N-terminal could more easily activate H2O2 to yield hydroxyl radical (.OH) than other Cu(II)-oligopeptide complexes containing histidyl residue in the second or third position. Further, it was suggested that since all Cu(II)-oligopeptide complexes examined could scavenge O2-, these complexes have SOD-like activities.
Ueda
J
J
National Institute of Radiological Sciences, Chiba-shi, Japan.
Ozawa
T
T
Miyazaki
M
M
Fujiwara
Y
Y
D000595:Amino Acid Sequence; D003300:Copper / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D016166:Free Radical Scavengers; D006639:Histidine / Q000378:metabolism*; D006861:Hydrogen Peroxide / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*; D013481:Superoxides / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism
D016166:Free Radical Scavengers; D009842:Oligopeptides; D017392:Thiobarbituric Acid Reactive Substances; D013481:Superoxides; D006639:Histidine; D003300:Copper; D006861:Hydrogen Peroxide; D013482:Superoxide Dismutase