Copper-sulfenate complex from oxidation of a cavity mutant of Pseudomonas aeruginosa azurin.

ABSTRACT: Metal-sulfenate centers are known to play important roles in biology and yet only limited examples are known due to their instability and high reactivity. Herein we report a copper-sulfenate complex characterized in a protein environment, formed at the active site of a cavity mutant of an electron transfer protein, type 1 blue copper azurin. Reaction of hydrogen peroxide with Cu(I)-M121G azurin resulted in a species with strong visible absorptions at 350 and 452 nm and a relatively low electron paramagnetic resonance gz value of 2.169 in comparison with other normal type 2 copper centers. The presence of a side-on copper-sulfenate species is supported by resonance Raman spectroscopy, electrospray mass spectrometry using isotopically enriched hydrogen peroxide, and density functional theory

SUBMITTER: Sieracki NA 

PROVIDER: S-EPMC3903256 | biostudies-literature | 2014 Jan

REPOSITORIES: biostudies-literature