Ptilomycalin A, a novel Na+, K(+)- or Ca2(+)-ATPase inhibitor, competitively interacts with ATP at its binding site

Eur J Pharmacol. 1996 Aug 22;310(1):95-8. doi: 10.1016/0014-2999(96)00482-7.

Abstract

Ptilomycalin A inhibited the brain Na+, K(+)-ATPase and Ca2(+)-ATPase from skeletal sarcoplasmic reticulum with an IC50 value of 2 microM and 10 microM, respectively. Kinetic analysis of the inhibitory effects of ptilomycalin A suggests that the inhibition of Na+, K(+)-ATPase is a competitive-, an uncompetitive- and an anticompetitive-type with respect to ATP, Na+ and K+, respectively. The inhibition of Ca2(+)-ATPase by ptilomycalin A is a competitive- or an uncompetitive-type with respect to ATP or Ca2+, respectively. These results suggest that ptilomycalin A interacts with ATP at the ATP binding site of Na+, K(+)-ATPase or Ca2(+)-ATPase. Ptilomycalin A has become a useful biochemical tool for clarifying the ATP binding site in both enzymes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenosine Triphosphate / metabolism*
  • Alkaloids / metabolism*
  • Animals
  • Binding Sites
  • Binding, Competitive
  • Brain / metabolism*
  • Calcium-Transporting ATPases / antagonists & inhibitors
  • Dose-Response Relationship, Drug
  • Guanidines
  • Sodium-Potassium-Exchanging ATPase / antagonists & inhibitors

Substances

  • Alkaloids
  • Guanidines
  • ptilomycalin A
  • Adenosine Triphosphate
  • Calcium-Transporting ATPases
  • Sodium-Potassium-Exchanging ATPase