[Isolation and basic properties of thiamine pyrophosphokinase from brewing yeast].

Thiamine pyrophosphokinase (EC 2.7.7.2) isolated from dry brewing yeast has been purified 20-fold with a 70% yield. Certain properties of the enzyme have been determined: pH and temperature optima, donor and acceptor concentrations, and relationship between the rate of cocarboxylase biosynthesis and the incubation time and the enzyme quantity. The effects of concentrations of bivalent metal ions Co2+, Mg2+ and Mn2+ on the rate of the enzymic reaction has been studied. A change in the pH optimum as a function of the nature of the ion-activator has been investigated. It has been shown that neopyrithiamin is a competitive inhibitor and oxythiamin inhibits the enzymic reaction insignificantly. Thiamine phosphate cannot be transformed into thiamine diphosphate by the purified enzyme.