Light induced surface potential changes in purple membranes and bacteriorhodopsin liposomes

Conference · Sun Jul 01 04:00:00 EDT 1979

OSTI ID:5926133

Carmeli, C; Quintanilha, A T; Packer, L

Bacteriorhodopsin, the retinal containing protein from the purple membrane of Halobacterium halobium, is known to function as an electrogenic light activated proton pump. On illumination, the chromophore undergoes a photocycle in which its retinal Schiff base is reversibly protonated. The detailed molecular mechanism of H/sup +/ translocation is not understood at present, but it may involve the Schiff base alone or other charge separation events, such as tyrosine deprotonation or charge displacement in tryptophan. These dissociation events could move along a sequence of amino acids thus providing a pathway for the protons across the purple membrane. Using continuous actinic light of moderate intensity and single turnover laser flashes we have studied the kinetics and stoichiometry of changes in surface charge that arise on purple membranes during proton release and binding.

• Research Organization: California Univ., Berkeley (USA). Lawrence Berkeley Lab.
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 5926133
• Report Number(s): LBL-9673; CONF-790766-1
• Country of Publication: United States
• Language: English

Related Subjects

550200 -- Biochemistry
550700* -- Microbiology
59 BASIC BIOLOGICAL SCIENCES
BACTERIA
BARYONS
BIOLOGICAL EFFECTS
BIOLOGICAL PATHWAYS
CELL CONSTITUENTS
CELL MEMBRANES
ELECTRIC POTENTIAL
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
FERMIONS
HADRONS
LASER RADIATION
LIPOSOMES
MEMBRANE TRANSPORT
MEMBRANES
MICROORGANISMS
NUCLEONS
ORGANOIDS
PIGMENTS
PROTONS
RADIATIONS
SURFACES
VISIBLE RADIATION