[Incorporation of synthetic phospholipids into the membranes of the sarcoplasmic reticulum from the rabbit muscle].
The hydrophobic spin label used in ESR showed that the iminoxyl radical rotation in the native membrane of sarcoplasmatic reticulum (SR) occurred much faster than in the membranes, modified by a synthetic lipid. Such effect was observed throughout the whole temperature range (7-40 degrees). Experimental technique for the modification of the SR membrane and the lipid by ultrasonic treatment has been developed. Synthetic lipids without ultrasonic treatment did not inhibit the activity of Ca2+-ATPase. The change in both the enzyme activity and its ability to transport the Ca2+ ions through the membrane vesicules was observed after the phospholipids incorporation into the SR membrane. The investigation of the temperature dependence (in Arrhenius coordinates) of native and modified by lecithin Ca2+-ATPase after ultrasonic treatment and also of a "pure enzyme" showed the presence of two sharp breaks at 20 degrees and 40-42 degrees. It was shown tha the break of an Arrhenius anamorphosis was caused by a lipid environment of ATPase, "melting" of a phospholipid bilayer. The break at 20-22 degrees was observed in all cases and even after the incorporation of all the lipids into the SR membrane. This phenomenon can be explained by the distortion of the protein-lipid interaction, affecting the conformation mobility of protein and the geometry of its catalytically active center.
D000818:Animals; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D004578:Electron Spin Resonance Spectroscopy; D007700:Kinetics; D008563:Membrane Lipids / Q000378:metabolism*; D009132:Muscles / Q000378:metabolism*; D010743:Phospholipids / Q000378:metabolism*; D011817:Rabbits; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*; D013113:Spin Labels; D013696:Temperature
D008563:Membrane Lipids; D010743:Phospholipids; D013113:Spin Labels; D000252:Calcium-Transporting ATPases
Vstraivanie sinteticheskikh fosfolipidov v membrany sarkoplazmaticheskogo retikuluma iz myshts krolika.