Substrate-Induced Carbon Monoxide Reactivity Suggests Multiple Enzyme Conformations at the Catalytic Copper M-Center of Peptidylglycine Monooxygenase.

ABSTRACT: The present study uses CO as a surrogate for oxygen to probe how substrate binding triggers oxygen activation in peptidylglycine monooygenase (PHM). Infrared stretching frequencies (ν(C ≡ O)) of the carbonyl (CO) adducts of copper proteins are sensitive markers of Cu(I) coordination and are useful in probing oxygen reactivity because the electronic properties of O₂ and CO are similar. The carbonyl chemistry has been explored using PHM WT and a number of active site variants in the absence and presence of peptidyl substrates. We have determined that upon carbonylation (i) a major CO band at 2092 cm^-1 and a second minor CO band at 2063 cm^-1 are observed in the absence of peptide substrate Ac-YVG; (ii) the presence of peptide substrate amplifies the minor CO b

SUBMITTER: Kline CD 

PROVIDER: S-EPMC5161237 | biostudies-literature | 2016 Dec

REPOSITORIES: biostudies-literature