title: Na,K-ATPase from Xenopus laevis kidney and epidermis: ouabain interaction studies.
abstract: A satisfactory purification from Xenopus laevis epidermis is presented. Ki and Kd values for the ouabain-enzyme interaction have been evaluated. Both parameters appear very low, as compared with those demonstrated in other anurans. Very low digitalis-like compound level was demonstrated in Xenopus; on the contrary in Bufo, in which these substances play a defensive role, it is very high. Our results strengthen the hypothesis of a physiological action of such compounds in regulating enzyme-driven Na+/K+ exchanges.
mesh_terms: D000818:Animals; D004817:Epidermis / Q000201:enzymology; D007668:Kidney / Q000201:enzymology*; D008861:Microsomes / Q000201:enzymology; D010042:Ouabain / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D014982:Xenopus laevis
chemical_list: D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase