An artificial CuII complex with intriguing oxygen radical-quenching profile. X-ray structure, cytochrome c assay, and ESR study.
A novel artificial peptide named HPH-Pep, comprising a pyridine and two histidine units, was synthesized. The HPH-Pep-CuII complex had unique pentacoordinated structure as shown by X-ray crystallography and exhibited superoxide-scavenging activity as indicated by ESR spectroscopy. The superoxide-quenching profile of HPH-Pep-CuII was studied in detail by cytochrome c assay and ESR spin trapping and it was found that (1) HPH-Pep-CuII did not scavenge hydrogen peroxide or hydroxyl radical and hence the scavenging activity was specific to superoxide, and (2) HPH-Pep-CuII did not generate hydrogen peroxide upon scavenging superoxide.
Otsuka
M
M
Institute for Chemical Research, Kyoto University, Japan.
Satake
H
H
Murakami
S
S
Doi
M
M
Ishida
T
T
Shibasaki
M
M
Sugiura
Y
Y
D003300:Copper / Q000378:metabolism*; D018360:Crystallography, X-Ray; D003574:Cytochrome c Group / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D005609:Free Radicals; D017665:Hydroxyl Radical / Q000378:metabolism; D008958:Models, Molecular; D010100:Oxygen / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000378:metabolism
D003574:Cytochrome c Group; D005609:Free Radicals; D017665:Hydroxyl Radical; D003300:Copper; D014969:Xanthine Oxidase; D010100:Oxygen