The effects of alkali metal ions on the acetate activating enzyme system.

The preparation and properties of an acetate activating enzyme’ from animal tissues have been described by Beinert et al. (1). In that work it had been noted that the sodium ion is a potent inhibitor of acetyl CoA formation in the acetate-ATP reaction. Nachmansohn and John (2) reported stimulation of the choline-acetylating system by potassium ion, while Korey et al. (3) reported the inhibition of the same system by sodium ion, although the high concentration required for inhibition led to the conclusion that the effect was non-specific. Our initial experiments with alkali metal ions and AAE carried out at the Institute for Enzyme Research, University of Wisconsin, have now been extended in this laboratory. It appeared that the ionic effects observed by Nachmansohn were, at least in part, on the acetate activating reaction.