[Effect of valinomycin on structural and functional transitions in sarcoplasmic reticulum membranes]

Abstract

Effect of valinomycin (VAL) on ATPase activity and transport of calcium ions in sarcoplasmic reticulum (SR) vesicles has been studied, as well as the diffusion efflux of calcium ions from liposomes of the total fraction of SR lipids. The studies were carried out in the temperature range of 10 divided by 50 degrees. Changes in the structure of SR membranes were checked with a fluorescent probe of 3-metoxibenzantron. It was shown that at the molar ratios 1:7000-1:70 VAL decreases its ATPase activity and active transport of calcium ions in SR at all temperatures. Besides VAL decreases the rapid efflux of calcium ions from SR and the diffusion efflux of calcium ions from liposomes within the temperature range 10 degrees divided by 35 degrees; it increases the rates of these processes at higher temperatures. Simultaneously the broadening of temperature intervals of structural transitions in the SR membranes takes place.