Highly Ouabain‐Sensitive α3 Isoform of Na⁺,K⁺‐ATPase in Human Brain

This is the authors' abstract. We don't add key points for this paper.

The Na + ,K + ‐ATPase α3 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 α3 isoform, has been found in human brainstem Na + ,K + ‐ATPase following formic acid treatment of the purified a isoform proteins. Human α3 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 α3 isoform in human brain. Na + ,K + ‐ATPase‐α1, α2, and α3 isoforms—Human and rat brainstem axolemma—Ouabain sensitivity—Formic acid treatment. Peng J. H. F. et al. Highly ouabain‐sensitive α3 isoform of Na + ,K + ‐ATPase in human brain. J. Neurochem. 58 , 1180–1183(1992).