par González-Mañas, Juan Manuel;Goñi, Félix Lix M F.M.;Tribout, Marianne;Paredes, Sergio
Référence Archives of biochemistry and biophysics, 282, 2, page (239-243)
Publication Publié, 1990-11
Référence Archives of biochemistry and biophysics, 282, 2, page (239-243)
Publication Publié, 1990-11
Article révisé par les pairs
Résumé : | The kinetics of purple membrane dark adaptation were studied at pH 5 and 7, in the presence and absence of the nonionic detergent Triton X-100. The effect of both sublytic and lytic surfactant concentrations has been considered. Our results show that: (a) dark adaptation is faster at pH 5 than at pH 7, (b) dark adaptation is slower, and of smaller amplitude, in the presence than in the absence of Triton X-100. The data may be interpreted in terms of a simple first-order kinetic model, according to which light-dark adaptation would depend basically on the equilibrium between the 13-cis-and the all-trans-isomers. The experiments also suggest that at pH 5, but not at pH 7, solubilizing surfactant concentrations produce a considerable increase in the velocity of the dark adaptation reaction, perhaps through changes in the microenvironment of a protonable group. © 1990. |