[Effect of phospholipases A2 from bee and cobra venom on the phospholipid composition and Na+-,K+-ATPase activity of synaptosomes].

The bee and cobra venom phospholipases A2 as well as partially acetylated cobra venom phospholipase A2 are studied for their effect on phospholipid composition of synaptosomes and their Mg2+- and Na+,K+-ATPase activity. It is established that these phospholipases induce the splitting of phosphatidylethanolamine, phosphatidylcholine and phosphatidylserine, inhibition of the Na+,K+-ATPase activity and activation of Mg2+-ATPase. Bee venom phospholipase A2 is more effective than cobra venom phospholipase A2, the both phospholipases splitting phosphatidylethanolamine most intensively.

[Lipid composition of different preparations of brain Na+, K+-ATPase].

The content and composition of phospholipids is determined in beef microsomal and synaptosomal fractions and also in these fractions preparations solubilized with triton X-100 (0.1%) and digitonin (0.2%).

[Characteristics of surface-active substances effect on K+-dependent phosphatase activity of brain tissue].

The K+-acetylphosphatase and K+-p-nitrophenylphosphatase activities in the fraction of brain microsomes were studied as affected by anionic (sodium desoxycholate and sodium dodecyl sulphate) and nonionic (triton X-100 and digitonin) surface-active substances. The most activating concentrations of these substances are determined and their similarity with those for Na+, K+-ATPase is marked. According to the character of the effect on the K+-phosphatase and Na+, K+-ATPase activities, the studied surface-active substances are grouped on the basis of the molecule configurations, rather than ionogenic factor.

[Extraction of highly active preparations of "soluble" Na+, K+-ATPase from different membrane stuctures of the brain].

A successive treatment with sodium iodide and digitonin of the myeline, microsome and synaptosome fractions of the cattle brain tissue resulted in obtaining the preparations of "soluble", Na+, K+-ATPase with a rather high specific activity non-containing practically Mg2+-dependent ATPase. To estimate the degree of these preparations structural heterogeneity they were subjected to analytical ultracentrifugation and disc-electrophoresis in polyacrylamide gel. The data obtained suggest an insignificant degree of heterogeneity for the "soluble" Na+, K+-ATP-ase preparations.

[Heterogeneity of protein metabolism and activities of certain enzymes in functionally different structures of nerve tissue].

The article deals with a review of the results of studies conducted at the department which evidence for inhomogeneity of localization, composition and different intensity of intravital renewal of proteins as well as for different activity of some enzymes most important for the nervous system functions in the macro- and microstructural formation of the nerve tissue. On the basis of the experimental data concerning the presence in the nerve tissue of a wide range of rates for intravital renewal of proteins in the structures of different functions as well as of those concerning subcellular and suborganoid localization of intracellular peptid-hydrolases, a conclusion is drawn that catabolism of the protein molecules occurs mainly on the cell membrane structures. The effect of acid peptide-hydrolases is chiefly manifested in the died and damaged cells and neutral ones in the intact functioning cells.