The Regulation of Glutamate Metabolism in Candida utilis

Abstract

An earlier observation that NAD-dependent glutamate dehydrogenase activity is modulated by rapid inactivation was extended to show that this mechanism is completely reversible. Changes in properties of the enzyme accompany inactivation and 2 different forms, active (a) and inactive (b) of the enzyme with distinctive properties were isolated. Incubation of the inactive enzyme with Mg in vitro produced a rapid increase of activity; this was accompanied by a change in the properties of the enzyme to those of the a form. This control mechanism of enzyme interconversion appears widespread among yeasts [Saccharomyces cerevisiae, Torulopsis candida, Pichia etchellsii, Metschnikowia pulcherrima and Rhodotorula glutinis]. Its probable role in modulating glutamate synthesis and degradation is discussed.