Mechanisms of Photochemical Energy Conversion by Chlorophyll: Progress Report, 1 July 1986-28 February 1989

摘要

Large and small unilamellar vesicles have been compared with respect to chlorophyll triplet quenching and electron transfer occurring at the inner and outer bilayer surfaces. Unexpectedly, large vesicles display inside-outside asymmetry, which is reversed in direction from that of small vesicles, indicating that factors in addition to lipid packing density asymmetry are responsible for the asymmetric behavior. Varying the ionic strength of the medium and the surface charge suggests that a transmembrane potential, in which the exterior surface is more negative than the interior, is also involved in causing asymmetry. Experiments using valinomycin indicate that ionophores, by generating electrostatic effects within the bilayer, exert more selective effects on membrane photochemical processes than do charges on the membrane surface. 3 refs. (ERA citation 14:014520)