[A comparative study of the ectophosphatase activity in different subpopulations of tumor cells].

Activities of ectophosphatases (alkaline phosphatase, 5'-nucleotidase and ecto-ATPase) from different subpopulation of lymphoma NKLy and ovary tumor of rats were investigated. A strong positive correlation has been shown between these activities in different subpopulations. A negative correlation between proliferative activity and activities of ectophosphatases was determined.

[Regulation of adenosine triphosphatase activity in mitochondria, chloroplasts and erythrocytes by anions, adenosine diphosphate and alcohols].

The effects of sulfite, bicarbonate, thiocyanate, methanol, ethanol, glycerol, dimethy sulfoxide and ADP on the ATPase activity of the coupling factor from liver mitochondria (F1) and pea chloroplasts (CF1) and of the anion-sensitive ATPase from rat erythrocytes were investigated. Under steady-state conditions of ATP hydrolysis catalyzed by F1, CF1, and erythrocyte ATPase, three Km values for each of the enzymes, three activation constants for sulfite and three inhibition constants for thiocyanate were determined. The efficiency and direction of the effects of anions, alcohols and ADP strongly depend on temperature and substrate (Mg-ATP) concentration.

[Properties of erythrocyte anion ATPase].

Properties of the anion ATPase from rat red blood cell membranes were investigated. Diethyl ether treated membranes exhibited the increased activity of the anion ATPase. Na+, K+- and Ca2+-ATPase activities were not found in these preparations.

[Kinetic parameters of anion adenosine triphosphatase of erythrocytes].

Effect of anions on kinetic properties of ATPase from rat erythrocyte membranes was studied. The ATPase activity was competitively inhibited by thiocyanate in mixtures containing sulfite. Thiocyanate, chlorine-anion, bicarbonate and sulfite affected noncompetitively the enzymatic activity as compared with Mg2+-ATP, ADP and calcium.

[Isolation and properties of anion-sensitive adenosine triphosphatase from erythrocyte membranes].

Using the non-ionic detergent Triton X-100 and gel-chromatography, an anion-sensitive ATPase was isolated from rat and rabbit erythrocyte membranes. The ATPase preparations possess no Na, K- or Mg, Ca-ATPase activities. ATPase from rat erythrocyte membranes is made up of five subunits with molecular weights of 58 000 (alpha), 50 000 (beta), 36 000 (gamma), 25 000 (delta) and 12 000 (epsilon) and can be represented by the formula alpha 3 beta 3 gamma delta epsilon.