Membrane properties of an extreme thermophile. II. Membrane functions underlying leucine transport and their relation with thermotropic phase transitions.
Various membrane properties of Thermus thermophilus HB8 were studied in order to elucidate the mechanism and implication of cell adaptation to a high temperature environment. 1. The profile of temperature dependence of the amino acid uptake rates was similar for the membrane obtained from cells grown at both 61 degrees C and 77 degrees C. 2. The remaining uptake activity after heat treatment paralleled the membrane potential generating ability, as measured by auramine O fluorescence response to the respiration substrate, and was not dependent on the growth temperature. 3. The temperature dependence of the efflux of the accumulated amino acid reflects the physical phase of the membrane and is dependent on the growth temperature.
D001692:Biological Transport; D002462:Cell Membrane / Q000378:metabolism* / Q000648:ultrastructure; D007700:Kinetics; D007930:Leucine / Q000378:metabolism*; D013696:Temperature; D013816:Thermodynamics; D013824:Thermus / Q000378:metabolism*
D007930:Leucine