Amino acid transport in Mycoplasma.
The uptake of l-histidine by Mycoplasma fermentans and l-methionine by M. hominis was found to be dependent on temperature and pH and to follow saturation kinetics. Several metabolic inhibitors inhibited this uptake. The transport system for l-methionine was highly specific. The l-histidine transport system was less specific, and the uptake was competitively inhibited by l-arginine and l-lysine. l-Histidine accumulated in the intracellular pool of M. fermentans at a concentration about 200 times that found in the medium. Efflux of accumulated l-histidine was demonstrated at 37 C, but not at 0 C. The rate of efflux was greatly accelerated by addition of l-histidine to the medium. The findings indicate that the Mycoplasma cell membrane contains specific transport systems resembling the permease systems of other microorganisms.
D000085:Acetates / Q000494:pharmacology; D000588:Amines / Q000494:pharmacology; D000596:Amino Acids / Q000494:pharmacology; D001151:Arsenic / Q000494:pharmacology; D001386:Azides / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002087:Butyrates / Q000494:pharmacology; D002247:Carbon Isotopes; D002729:Chloromercuribenzoates / Q000494:pharmacology; D003486:Cyanides / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D006639:Histidine / Q000378:metabolism*; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007461:Iodoacetates / Q000494:pharmacology; D007700:Kinetics; D008715:Methionine / Q000378:metabolism*; D009174:Mycoplasma / Q000187:drug effects / Q000378:metabolism*
D000085:Acetates; D000588:Amines; D000596:Amino Acids; D001386:Azides; D002087:Butyrates; D002247:Carbon Isotopes; D002729:Chloromercuribenzoates; D003486:Cyanides; D007461:Iodoacetates; D006639:Histidine; D008715:Methionine; D001151:Arsenic; D005033:Ethylmaleimide