(Mechanism of proton pumping by bacteriorhodopsin). Progress report

Technical Report · Sat Dec 31 23:00:00 EST 1983

OSTI ID:5484138

Several discoveries that we believe will impact on the study of light energy transduction by bacteriorhodopsin are described. First we reported that removal of the C-terminal tail of bacteriorhodopsin caused a large decrease in the number of protons released by light. Second, we showed that proteolysis of bacteriorhodopsin cell envelope vesicles led to a similar affect on the protons pumped by light. Third, we have begun studies and reported preliminary results on using fluorescent dyes coupled to carboxyl groups on the C-terminal tail to study the conformation of the tail as a function of environmental conditions. Fourth, we have also made a correlation between a particular photocycle intermediate, the slowly decaying form of M, and proton pumping by light absorbed by M/sup slow/, a similar pH dependence, and a similar temperature dependence. Fifth, we have shown that bacteriorhosopsin binds calcium and magnesium very tightly. Removal of these divalent cations had a very large effect on the color, photochemistry, and proton pumping by bacteriorhodopsin. Finally, we have made monoclonal determinants of bacteriorhodopsin and are using these antibodies in several different ways to study bacteriorhodopsin. 8 refs.

• Research Organization: Illinois Univ., Urbana (USA). Dept. of Physiology and Biophysics
• DOE Contract Number: AC02-82ER12087
• OSTI ID: 5484138
• Report Number(s): DOE/ER/12087-T2; ON: DE85014280
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
140505 -- Solar Energy Conversion-- Photochemical
Photobiological
& Thermochemical Conversion-- (1980-)
550200* -- Biochemistry
59 BASIC BIOLOGICAL SCIENCES
ANTIBODIES
CHEMICAL REACTIONS
CONFORMATIONAL CHANGES
DECOMPOSITION
MEMBRANE TRANSPORT
MEMBRANES
MONOCLONAL ANTIBODIES
ORGANIC COMPOUNDS
PHOTOSYNTHETIC MEMBRANES
PIGMENTS
PROTEINS
PROTEOLYSIS
RHODOPSIN