Kinetic studies of phototransients in bacteriorhodopsin

Interaction of ionophores with bacteriorhodopsin

“…halobium and isolation of PM the method in [2] was used with slight modifications. Flash photometric techniques were used, as in [5]. Decay profiles of 412 nm and recovery of the ground state chromatophore at 570 nm were analyzed and the half-life times for these parameters were calculated.…”

“…Decay profiles of 412 nm and recovery of the ground state chromatophore at 570 nm were analyzed and the half-life times for these parameters were calculated. Plots exhibiting biphasicity were analyzed by resolving into first-order exponentials graphically by the curve pealing method [5].…”

“…The photocycle can be described by the scheme: bRs70 _+ K590 + ~550 + ~412 (0660) where the numbers refer to the approximate wavelength maxima of the transients [4]. In a conventional flash photolysis system, as in [5], the absorption band of bRs7' centered at 570 nm, is temporarily bleached, while A412 and Abe0 max are observed. The appearance of the proton in the bulk phase is related to the formation of M412.…”

“…M412 was stabilized [6] by suspending PM in 4 M NaCl saturated with diethylether. Based on the observation [5] that high concentrations of valinomycin slow down the decay of M412, also various ionophoric compounds were tried in order to increase in a controlled manner the steady state concentration of M412 [7,8]. It was found that the combined use of two ionophores, beauvericin (BV) and valinomycin (VL), cause a remarkable increment in the steady state…”

Integrated optical application of bacteriorhodopsin

“…4 [28,[30][31][32][33][34][35]. The late intermediate states are also photosensitive, the photocycle can be short-cut at any step by applying a second flash exciting the corresponding intermediate state [36,37].…”