Highly ouabain-sensitive alpha 3 isoform of Na+,K(+)-ATPase in human brain.
The Na+,K(+)-ATPase alpha 3 isoform has recently been demonstrated immunochemically in human brain. Conclusive biochemical evidence, however, is still lacking. In this study, a unique 50-kDa polypeptide, which is known to be specific to the rat alpha 3 isoform, has been found in human brainstem Na+,K(+)-ATPase following formic acid treatment of the purified alpha isoform proteins. Human alpha 3 Na+,K(+)-ATPase is also highly sensitive to ouabain inhibition, with a 50% ouabain inhibition value of 1.0 x 10(-7) M. These results provide clear and direct evidence for the existence of the alpha 3 isoform in human brain.
Peng
J H
JH
Department of Pathology, University of Missouri-Kansas City School of Medicine 64108.
Zeng
Y C
YC
Parker
J C
JC
D000818:Animals; D001369:Axons / Q000201:enzymology; D001921:Brain / Q000201:enzymology*; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D007536:Isomerism; D010042:Ouabain / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*
D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase