Chloride Ion Modulation of the Fast Photoelectric Signal in Halorhodopsin ThinFilms

摘要

We report on studies of the fast photoelectric response of reconstitutedhalorhodopsin thin films. Oriented halorhodopsin thin films were deposited onto a thin Teflon film (6 microns), either from purified halorhodopsin membrane fragments or from halorhodopsin phospholipid vesicles. We found a fast photoelectric signal with two components, which are analogous to those generated in bacteriorhodopsin thin films. Therefore we use similar terminology to describe the two components: H1 and H2. The H2 component is sensitive to replacement of the bathing KC1 solution with a chloride free medium, but the H1 component is not. A comparison with the analogous components in bacteriorhodopsin thin films is presented. Implications for molecular electronics are discussed. The plasma membrane of Halobacterium halobium is known to contain four retinal proteins which act as light energy or light signal transducers.