Vanadate is a potent (Na,K)-ATPase inhibitor found in ATP derived from muscle.

L.C Cantley,L Josephson,R Warner,M Yanagisawa,C Lechene,G Guidotti

doi:10.1016/s0021-9258(17)40978-1

Abstract

A potent (Na,K)-ATPase inhibitor purified from "Sigma Grade* ATP has been identified as vanadium using electron probe microanalysis and confirmed by microwave-induced emission spectroscopy and electron paramagnetic resonance spectroscopy. Sodium orthovanadate (Na3 VO4) is identical with the purified inhibitor with respect to ultraviolet absorbance, migration on thin layer chromatography, and inhibition of (Na,K)-ATPase. The (Na,K)-ATPase is in-inhibited 50% by 40 nM Na3 VO4 under optimal conditions (28 mM Mg2+) and the inhibition is 100% reversible by millimolar concentrations of norepinephrine. The physiological significance of this inhibition is discussed in relation to vanadium concentrations in vivo.

Highlights

The inhibitor was present in an equine muscle extract used by Sigma Chemical Co. as a source of ATP and was present in a Ba”+-precipitable fraction from rabbit muscle
We report evidence proving that this inhibitor is vanadium in the +5 oxidation state and discuss the possible physiological significance of this finding
Sodium orthovanadate was used as a standard to measure vanadium concentrations

Summary

Resource in Electron Probe

A potent (Na,K)-ATPase inhibitor purified from “Sigma Grade” ATP has been identified as vanadium using electron probe microanalysis and confirmed by microwave-induced emission spectroscopy and electron paramagnetic resonance spectroscopy. We have separated a potent (Na,K)-ATPase inhibitor from Sigma Grade ATP [10]. This inhibitor was shown to have a Mg2+ and K+ requirement for inhibition and to exhibit a noncompetitive inhibition constant, K,, of approximately nM under optimal conditions. The inhibitor was present in an equine muscle extract used by Sigma Chemical Co. as a source of ATP and was present in a Ba”+-precipitable fraction from rabbit muscle. In this communication, we report evidence proving that this inhibitor is vanadium in the +5 oxidation state and discuss the possible physiological significance of this finding

AND METHODS

The purified inhibitor from Sigma Grade ATP was concentrated to approximately

Selenium Vanadium Zinc

DISCUSSION