Effects of polyamines on partial reactions of membrane (Na+ + K+)-ATPase

Gregory Quarfoth, Khalil Ahmed, Donald Foster

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6 Scopus citations


Spermine and spermidine inhibit the (Na+ + K+)-ATPase (ATP phosphohydrolase, EC reaction so that the effect increases as the ionic content due to Na+ and K+ in the reaction is reduced. Several other amines inhibit (Na+ + K+)-ATPase to varying degress and methylglyoxal-bis(guanylhydrazone) was the most potent inhibitor among those tested. The inhibition by polyamines of the ATPase is uncompetitive with respect to Mg2+ and ATP activation of the reaction. Various naturally occurring polyamines and other amines inhibited Na+ activation of (Na+ + K+)-ATPase as well as Na+-dependent phosphoenzyme formation in an apparently competitive manner with respect to Na+. Likewise, K+-activation of (Na+ + K+)-ATPase as well as K+-p-nitrophenyl phosphatase was inhibited in an apparently competitive manner with respect to K+. Both the cation charge and structure (e.g., aliphatic chain length) may contribute to the inhibitory effects of the amines; however, Na+ sites appear to be more sensitive to cation charge than the aliphatic chain length of the amine, whereas the opposite appears to be true for K+ sites. The results do not indicate a specific effect of polyamines on (Na+ + K+)-ATPase or its partial reactions.

Original languageEnglish (US)
Pages (from-to)580-590
Number of pages11
JournalBBA - Enzymology
Issue number2
StatePublished - Oct 12 1978


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