A spin-label study of protein-lipid interaction in sarcoplasmic reticulum of rabbit skeletal muscle.
Whether or not the thermotropic change at about 18 degrees C in the physical state of Ca2+-ATPase protein molecules of sarcoplasmic reticulum membranes could be transmitted to lipids through protein-lipid interactions was investigated using a spin-label technique. Fatty acid spin labels were used to probe the bulk membrane lipids while long-chain spin labels attached at one end to the Ca2+-ATPase molecules through a covalent bond were used to monitor the boundary lipids. The results on the temperature-dependence of alkyl-chain flexibility of lipid molecules indicate that the change in the state of the protein molecules is accompanied by one of the boundary lipids, but not of the bulk lipids.
D000818:Animals; D001665:Binding Sites; D000252:Calcium-Transporting ATPases / Q000032:analysis*; D004578:Electron Spin Resonance Spectroscopy; D008563:Membrane Lipids / Q000032:analysis*; D008565:Membrane Proteins / Q000032:analysis*; D009124:Muscle Proteins / Q000032:analysis*; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000032:analysis*; D013816:Thermodynamics
D008563:Membrane Lipids; D008565:Membrane Proteins; D009124:Muscle Proteins; D000252:Calcium-Transporting ATPases