Replacement of Mn(III) with Cu(II) in Bacillus stearothermophilus superoxide dismutase. Similarity of the active site to the zinc site of copper/zinc superoxide dismutase.
Copper(II) was substituted for manganese(III) in Bacillus stearothermophilus Mn-superoxide dismutase. The (EPR) spectrum of the Cu(II) is distinctly rhombic, overlapping that of Cu(II) replacing zinc in copper/zinc superoxide dismutase. The copper-cyanide complex of the bacterial enzyme gives an EPR spectrum nearly identical to the cyanide-copper complex of the Cu/Zn enzyme, indicating three nitrogens as metal ligands. These results support the suggestion that metal coordination in B. stearothermophilus Mn-dismutase is a tetrahedral arrangement of three imidazoles and a carboxylate group and indicate copper as a good spectroscopic probe for studying the active site of Mn- and Fe-superoxide dismutases.
Bannister
J V
JV
Desideri
A
A
Rotilio
G
G
D001665:Binding Sites; D003300:Copper / Q000378:metabolism*; D003486:Cyanides / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D008345:Manganese / Q000378:metabolism*; D013482:Superoxide Dismutase / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
D003486:Cyanides; D008345:Manganese; D003300:Copper; D013482:Superoxide Dismutase; D015032:Zinc