The activation of l-threonine dehydrogenase by potassium ions

Publisher Website
Google Scholar
Abstract
Staphylococcus aureus threonine dehydrogenase is partially inactivated by dialysis against water, but the dialysed enzyme can be activated by incubation with KC1 at 0[degree]. Maximal activation requires incubation in 0.5 [image],-KCl for 24 hr. The activation is unaffected by the presence of EDTA. The enzyme is activated by Rb+, Cs+, K+, NH4+ and to a smaller extent by Li+ and Na+ ions. As well as the time dependent activation, the enzymic activity is stimulated by the addition of KC1 to the assay mixture. The specificities of the 2 activating effects are similar. The active form of the enzyme is probably a K+ ion-apoenzyme complex. The K+ ions in the assay mixture may act by maintaining the equilibrium in favor of complex-formation.