Infrared spectroscopic studies of Acholeplasma laidlawaii B membranes. Comparison of the gel to liquid-crystal phase transition in intact cells and isolated membranes.
The physical state of the membrane lipids in the plasma membranes of intact, live Acholeplasma laidlawii B cells was probed by Fourier-transform infrared spectroscopy and compared with that in isolated membranes. Infrared spectra of live A. laidlawii B cells, enriched biosynthetically in the presence of avidin, with saturated deuterated and unsaturated non-deuterated fatty acids have been recorded at a variety of temperatures. The results indicate that within the temperature range of the gel to liquid-crystal phase transition, the live cells are able to keep the 'fluidity' of their plasma membranes at a considerably higher value compared to that in the isolated membranes at the same temperature. While this is a generally valid observation, the degree by which live and isolated membranes differ in their liquid-crystal-phase content at a given temperature depends on the nature of the exogenous fatty acid and the temperature of growth.
Mantsch
H H
HH
Division of Chemistry, National Research Council of Canada, Ottawa.
Yang
P W
PW
Martin
A
A
Cameron
D G
DG
D000127:Acholeplasma / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism*; D006868:Hydrolysis; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D011489:Protein Denaturation; D013055:Spectrophotometry, Infrared; D013696:Temperature
D008563:Membrane Lipids; D008565:Membrane Proteins