[5'-Nucleotidase activity of lymphocyte plasma membranes. Effect of concanavalin A].
The 5'-nucleotidase properties of isolated lymphocyte plasma membranes from young pig mesenteric nodes are described; nucleosides-5'-monophosphates are the substrates of this specific enzyme. Concanavalin A inhibits this enzyme; on the same membranes this mitogen does not affect alkaline phosphatase and activates the membrane bound (Ca2+) ATPase. The 5'-nucleotidase inhibition is due to a specific interaction of Con A with carbohydrate groups of the membrane; its high positive cooperativity suggests that the lectin promotes reorganization of the membrane bound 5'-nucleotidase. Solubilization of the 5'-nucleotidase does not prevent the effect of Con A and the solubilized enzyme is firmly bound by Con A-Sepharose 4B; these results suggest that Con A inhibits the enzyme by a direct interaction and that 5'-nucleotidase can be considered as an eventual receptor for the lectin.
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D002118:Calcium / Q000494:pharmacology; D002462:Cell Membrane / Q000201:enzymology; D002846:Chromatography, Affinity; D003208:Concanavalin A / Q000494:pharmacology*; D004789:Enzyme Activation; D007700:Kinetics; D008214:Lymphocytes / Q000201:enzymology*; D009708:Nucleotidases / Q000302:isolation & purification / Q000378:metabolism*; D011952:Receptors, Concanavalin A / Q000378:metabolism; D013552:Swine
D011952:Receptors, Concanavalin A; D003208:Concanavalin A; D009708:Nucleotidases; D000469:Alkaline Phosphatase; D000251:Adenosine Triphosphatases; D002118:Calcium
Activité 5'-nucléotidase des membranes plasmiques de lymphocytes. Effet de la concanavaline A.