The basic intensity dependent optical properties of photoactive yellow
protein were studied and shown to resemble to those of bacteriorhodop
sin, Using a set of rate equations and a modified photocycle the trans
mittance behaviour was explained. Fitting the theoretical intensity de
pendent transmittance curves to the measurements was done by adjusting
the photochemical parameters and the relaxation times. The model expl
ains the experiments. (C) 1998 Elsevier Science B.V. All rights reserv
ed.