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Femtosecond absorption spectroscopy of cytochrome c oxidase: Excited electronic states and relaxation processes in heme a and heme a 3 centers

Research paper by I. V. Shelaev, F. E. Gostev; T. V. Vygodina; S. V. Lepeshkevich; B. M. Dzhagarov

Indexed on: 28 Feb '18Published on: 01 Jan '18Published in: High Energy Chemistry



Abstract

Cytochrome c oxidase, the key bioenergetic protein, was studied by femtosecond absorption spectroscopy. Time-resolved spectral characteristics of the difference spectra recorded in the timescale from 80 fs to 20 ps were analyzed. Electronic relaxation of the excitation energy in heme a occurs in three successive steps. After completion of these steps, heme a is in the excited vibrational state of the ground state. Vibrational relaxation, cooling of the heme, occurs for several picoseconds.