Isolation of calcium pump system and purification of calcium ion-dependent ATPase from heart muscle |
| |
Authors: | DO Levitsky MK Aliev AV Kuzmin TS Levchenko VN Smirnov EI Chazov |
| |
Institution: | Laboratory of Cardiac Metabolism, All-Union Research Center of Cardiology, U.S.S.R. Academy of Medical Sciences, Moscow U.S.S.R. |
| |
Abstract: | The procedure for the isolation of the highly active fraction of sarcoplasmic reticulum from pigeon and dog hearts is described. The method is based on the partial loading of heart microsomes with calcium and oxalate ions and the precipitation of loaded vesicles in sucrose and potassium chloride concentration gradients. Preparations obtained possess high activity of Ca2+-dependent ATPase and are also able to accumulate up to 10 μmol Ca2+ per mg protein. Purification of sarcoplasmic reticulum membranes is accompanied by a decrease in concentration of cytochrome a+a3 and an increase in the content of 32P]phosphoenzyme. The basic components in “calcium-oxalate preparation” from hearts are proteins with molecular weights of about 100 000 (Ca2+-dependent ATPase) and 55 000 Calcium-oxalate preparation from pigeon hearts was used for subsequent purification of Ca2+-dependent ATPase. Specific activity of purified enzyme from pigeon hearts is 12–16 μmol Pi/min per mg protein. Enzyme activity of purified Ca2+-dependent ATPase is inhibited by EGTA and is not sensitive to azide, 2,4-dinitrophenol and ouabain. The data obtained demonstrate the similarity of calcium pump systems and Ca2+-dependent ATPases isolated from heart and skeletal muscles. |
| |
Keywords: | EGTA PPO 2 5-diphenyloxazole POPOP 1 4-bis-(5-phenyloxazolyl-2)-benzene |
本文献已被 ScienceDirect 等数据库收录! |