Light-induced generation of electric potential difference in membranes of purple and green sulfur bacteria.
When associated with a planar phospholipid membrane, chromatophores isolated from photosynthetic sulfur bacteria Chromatium minutissimum, Ectothiorhodospira shaposhnikovii, and Chlorobium limicola f. thiosulfatophilum were shown to generate a light-induced transmembrane electric potential difference measured by a direct method using macroelectrodes and a voltmeter. The maximal photoelectric responses were observed upon the addition of 1,4-naphthoquinone in combination with phenazine methosulfate (or TMPD) and ascorbate. The photoeffects were inhibited by CCCP and gramicidin. The data demonstrate that similar mechanisms of photoelectric generation function in membranes of the different bacteria studied.
Krasinskaya
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NP
Department of Microbiology, Biological Faculty, Moscow State University, Moscow 117234, USSR.
Samuilov
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D001205:Ascorbic Acid; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone / Q000494:pharmacology; D041883:Chlorobium / Q000378:metabolism / Q000528:radiation effects*; D002844:Chromatium / Q000378:metabolism / Q000528:radiation effects*; D020587:Ectothiorhodospira / Q000378:metabolism / Q000528:radiation effects*; D006096:Gramicidin / Q000494:pharmacology; D008027:Light; D008564:Membrane Potentials / Q000187:drug effects / Q000528:radiation effects*; D008773:Methylphenazonium Methosulfate; D009285:Naphthoquinones
D009285:Naphthoquinones; D006096:Gramicidin; D008773:Methylphenazonium Methosulfate; D002258:Carbonyl Cyanide m-Chlorophenyl Hydrazone; D001205:Ascorbic Acid; C035342:1,4-naphthoquinone