Abstract

Our ultimate goal is to understand the molecular basis of the process of visual phototransduction performed by visual pigments. Our approach is to solubilize and purify rhodopsin from both vertebrate and invertebrate and then to reassemble it into model lipid bilayers that allow measurements that are not readily achieved otherwise. Rhodopsin has been incorporated into planar bilayers which separate two aqueous compartments and are readily amenable for electrical measurements. Furthermore, asymmetric bilayers containing rhodopsin only on one monolayer are formed by apposing a lipid monlayer to a rhodopsin-lipid monolayer. The effect of light on this system is to induce the formation of a voltage-sensitive channel. The kinetics of channel opening and closing, and the ion-selectivity of the channel are under current investigation. Rhodopsin is also incorporated into bilayer vesicles, with diameters of several micrometers. The optical spectral properties of rhodopsin in the vesicles are similar to those recorded in retinal rod disc membranes by chemical, optical and electrical techniques.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY002084-08
Application #
3256494
Study Section
(VID)
Project Start
1978-04-01
Project End
1985-10-31
Budget Start
1985-07-01
Budget End
1985-10-31
Support Year
8
Fiscal Year
1985
Total Cost
Indirect Cost

  Institution

Name
University of California San Diego
Department
Type
Schools of Arts and Sciences
DUNS #
077758407
City
La Jolla
State
CA
Country
United States
Zip Code
92093

  Publications

Borochov-Neori, H; Montal, M (1989) Rhodopsin-G-protein interactions monitored by resonance energy transfer. Biochemistry 28:1711-8
Montal, M; Hartshorne, R; Keller, B (1987) Studies on sodium channels reconstituted in lipid bilayers: inferences about molecular mechanisms derived from single-channel recordings. Soc Gen Physiol Ser 41:149-65
Hellingwerf, K J (1987) Reaction centers from Rhodopseudomonas sphaeroides in reconstituted phospholipid vesicles. II. Light-induced proton translocation. J Bioenerg Biomembr 19:225-38
Hellingwerf, K J (1987) Reaction centers from Rhodopseudomonas sphaeroides in reconstituted phospholipid vesicles. I. Structural studies. J Bioenerg Biomembr 19:203-23
Keller, B U; Hartshorne, R P; Talvenheimo, J A et al. (1986) Sodium channels in planar lipid bilayers. Channel gating kinetics of purified sodium channels modified by batrachotoxin. J Gen Physiol 88:1-23
Hamamoto, T; Montal, M (1986) Functional reconstitution of bacterial cytochrome oxidases in planar lipid bilayers. Methods Enzymol 126:123-38
Blatt, Y; Montal, M S; Lindstrom, J M et al. (1986) Monoclonal antibodies specific to the beta and gamma subunits of the Torpedo acetylcholine receptor inhibit single-channel activity. J Neurosci 6:481-6
Hartshorne, R P; Keller, B U; Talvenheimo, J A et al. (1986) Functional reconstitution of purified sodium channels from brain in planar lipid bilayers. Ann N Y Acad Sci 479:293-305
Hamamoto, T; Carrasco, N; Matsushita, K et al. (1985) Direct measurement of the electrogenic activity of o-type cytochrome oxidase from Escherichia coli reconstituted into planar lipid bilayers. Proc Natl Acad Sci U S A 82:2570-3
Hartshorne, R P; Keller, B U; Talvenheimo, J A et al. (1985) Functional reconstitution of the purified brain sodium channel in planar lipid bilayers. Proc Natl Acad Sci U S A 82:240-4

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