The electron-transfer reaction between azurin and the cytochrome c oxidase from Pseudomonas aeruginosa

摘要: A stopped-flow investigation of the electron-transfer reaction between oxidized azurin and reduced Pseudomonas aeruginosa cytochrome c-551 oxidase Ps. was performed. Electrons leave enter molecule via its haem c component, with oxidation reduction d1 occurring by internal electron transfer. The mechanism in both directions is complex. In direction oxidation, two phases assigned on basis difference spectra to proceed rate constants 3.2 X 10(5)M-1-S-1 2.0 10(4)M-1-S-1, whereas occurs at 0.35 +/- 0.1S-1. Addition CO enzyme profoundly modifies faster process tending towards a limit 200S-1. Reduction similarly complex, fast phase 120S-1, slower second-order 1.5 10(4)M-1-S-1; transfer this o.25 These results have been applied kinetic model originally developed from temperature-jump studies.