A novel setup for time-resolved IR spectroscopy on Cytochrome c Oxidase

Cytochrome c oxidase: structure and spectroscopy.

Cytochrome c oxidase, the terminal enzyme of the respiratory chains of mitochondria and aerobic bacteria, catalyzes electron transfer from cytochrome c to molecular oxygen, reducing the latter to water. Electron transfer is coupled to proton translocation across the membrane, resulting in a proton and charge gradient that is then employed by the F0F1-ATPase to synthesize ATP. Over the last year...

Time-Resolved Resonance Raman Study on Oxygen Activation by Cytochrome c Oxidase in Intact Whole Mitochondria

Probing the Q-proton pathway of ba3-cytochrome c oxidase by time-resolved Fourier transform infrared spectroscopy.

In cytochrome c oxidase, the terminal respiratory enzyme, electron transfers are strongly coupled to proton movements within the enzyme. Two proton pathways (K and D) containing water molecules and hydrophobic amino acids have been identified and suggested to be involved in the proton translocation from the mitochondrial matrix or the bacterial cytoplasm into the active site. In addition to the...

Time-resolved optical absorption studies of cytochrome oxidase dynamics.

Time-resolved spectroscopic studies in our laboratory of bovine heart cytochrome c oxidase dynamics are summarized. Intramolecular electron transfer was investigated upon photolysis of CO from the mixed-valence enzyme, by pulse radiolysis, and upon light-induced electron injection into the cytochrome c/cytochrome oxidase complex from a novel photoactivatable dye. The reduction of dioxygen to wa...

Time-resolved resonance Raman study of dioxygen reduction by cytochrome c oxidase

Six oxygen-associated vibrations were observed for reaction intermediates of bovine cytochrome c oxidase with 0, using time-resolved resonance Raman spectroscopy at room temperature. The isotope frequency shifts for 160180, have established that the primary iqtermediate is an end-on type dioxygen adduct of Fea3, which is followed by two oxoheme intermediates, and that the final intermediate app...