Unknown

Dataset Information

0

Novel tripeptide model of nickel superoxide dismutase.


ABSTRACT: Nickel superoxide dismutase (Ni-SOD) catalyzes the disproportionation of superoxide to molecular oxygen and hydrogen peroxide, but the overall reaction mechanism has yet to be determined. Peptide-based models of the 2N:2S nickel coordination sphere of Ni-SOD have provided some insight into the mechanism of this enzyme. Here we show that the coordination sphere of Ni-SOD can be mimicked using the tripeptide asparagine-cysteine-cysteine (NCC). NCC binds nickel with extremely high affinity at physiological pH with 2N:2S geometry, as demonstrated by electronic absorption and circular dichroism (CD) data. Like Ni-SOD, Ni-NCC has mixed amine/amide ligation that favors metal-based oxidation over ligand-based oxidation. Electronic absorption, CD, and magnetic CD (MCD) data collected for Ni-NCC are consistent with a diamagnetic Ni(II) center bound in square-planar geometry. Ni-NCC is quasi-reversibly oxidized with a midpoint potential of 0.72(2) V (vs Ag/AgCl) and breaks down superoxide in an enzyme-based assay, supporting its potential use as a model for Ni-SOD chemistry.

SUBMITTER: Krause ME 

PROVIDER: S-EPMC2810650 | biostudies-literature | 2010 Jan

REPOSITORIES: biostudies-literature

altmetric image

Publications

Novel tripeptide model of nickel superoxide dismutase.

Krause Mary E ME   Glass Amanda M AM   Jackson Timothy A TA   Laurence Jennifer S JS  

Inorganic chemistry 20100101 2


Nickel superoxide dismutase (Ni-SOD) catalyzes the disproportionation of superoxide to molecular oxygen and hydrogen peroxide, but the overall reaction mechanism has yet to be determined. Peptide-based models of the 2N:2S nickel coordination sphere of Ni-SOD have provided some insight into the mechanism of this enzyme. Here we show that the coordination sphere of Ni-SOD can be mimicked using the tripeptide asparagine-cysteine-cysteine (NCC). NCC binds nickel with extremely high affinity at physi  ...[more]

Similar Datasets

| S-EPMC1217701 | biostudies-other
| S-EPMC3010328 | biostudies-literature
| S-EPMC6853177 | biostudies-literature
| S-EPMC3059394 | biostudies-literature
| S-EPMC423235 | biostudies-literature
| S-EPMC4405897 | biostudies-literature
2021-12-31 | GSE158237 | GEO
| S-EPMC6965706 | biostudies-literature
| S-EPMC3752415 | biostudies-literature
| S-EPMC4635969 | biostudies-literature