[Localization of gramicidin S on the cytoplasmic membrane of Bacillus brevis and its effect on the activity of membrane enzymes].
It was shown that malate dehydrogenase of isolated membranes of the gramicidin S producer Bacillus brevis var. G.-B. (R.-form) is completely inhibited by the antibiotic (approximately 200 mkg/mg of protein). Succinate and NADH dehydrogenases at concentration up to 1 mg per mg of protein are insensitive to it, while corresponding oxidases are inhibited by the antibiotic not more than by 65 -- 75% apparently due to partial damage of the terminal parts of the respiratory chain. The respiration of the producer intact cells is inhibited by exogenous gramicidin S by not more than 55 -- 60%, while the respiration of antibiotic-sensitive cells of M.lysodeikticus is inhibited completely. It was shown that phosphatidyl ethanolamine (50%), phosphatidyl glycerol (15% and diphosphatidyl glycerol (25%) are the major phospholipid components of the membranes of the given strain of Bac. brevis. It was assumed that the resistance of Bac. brevis cells to gramicidin S is partly due to the constant ratio of the charged and amphoteric phospholipids. Using 31P-NMR spectroscopy, the kinetics of free phosphoric compounds in the cells and cell extracts of Bac. brevis during culture growth and gramicidin S synthesis were studied. The content of carbohydrate monophosphate, remained unaffected, while that of nucleoside di- and triphosphates and dinucleotides was low and at definite density and gramicidin S content (above 100 mkg/ml) fell down below the resolution capacity of the method employed. Evidence for gramicidin S localization of the Bac. brevis membrane and possible causes for the manifestation of the NADH dehydrogenase activity at a certain stage of culture growth are discussed.
D001407:Bacillus / Q000201:enzymology*; D002462:Cell Membrane / Q000201:enzymology; D003579:Cytochrome Reductases / Q000378:metabolism*; D006096:Gramicidin / Q000502:physiology*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008291:Malate Dehydrogenase / Q000378:metabolism*; D008563:Membrane Lipids / Q000502:physiology; D009245:NADH Dehydrogenase / Q000378:metabolism*; D010743:Phospholipids / Q000502:physiology; D013385:Succinate Dehydrogenase / Q000378:metabolism*
D008563:Membrane Lipids; D010743:Phospholipids; D006096:Gramicidin; D008291:Malate Dehydrogenase; D013385:Succinate Dehydrogenase; D003579:Cytochrome Reductases; D009245:NADH Dehydrogenase
Lokalizatsiia gramitsidina S na tsitoplazmaticheskoĩ membrane bakteriĩ-produtsenta Bacillus brevis i ego deĩstvie na aktivnost' membrannykh fermentov.