KINETIC MODEL OF BACTERIORHODOPSIN PHOTOCYCLE: PATHWAY FROM M STATE TO bR

Abstract
A model of the last parts of the bacteriorhodopsin (bR) photocycle is proposed on the basis of experimental data for the kinetic behaviour of the ''O'' intermediate during a temperature pulse in distilled water suspension. The model includes the previously proposed (but not well characterized) intermediate ''N'' between the ''M'' and ''O'' states of bR. This intermediate exists in fast temperature-dependent quasistationary equilibrium with the red-shifted intermediate ''O'' and has a maximum of absorption close to the bR spectrum.