Regulation of Alanine Dehydrogenase in Bacillus licheniformis

Abstract

Cell extracts of Bacillus licheniformis were found to contain nicotinamide adenine dinucleotide (NAD)-dependent L-alanine dehydrogenase (ADH) (Lalanine:NAD oxidoreductase, EC 1.4.1.1)'. High specific activities (3.5 to 6.0 IU/mg of protein) were found in extracts of cells throughout growth cycles only when L-alanine served as the primary source of carbon or carbon and nitrogen.Specific activities were minimal (0.02 to 0.04 IU/mg of protein) during growth on' glucose, but increased at least sevenfold during the first 5 h of postlogarithmicphase metabolism. Addition of 10 mM glucose to cultures during logkrithmicphase growth on L-alanine resulted in a rapid decrease in enzyme activity. Addition of 20 mM L-alanine to cells near the completion of log-phase growth on glucose resulted in a 20-fold increase in ADH specific activity during less than one cell generation. Extracts of postlogarithmic-phase cells cultured on glucose, malate, L-glutamate, or Casamino Acids contained intermediate levels of ADH activity. The enzyme was partially purified from crude extracts of B. licheniformis, and apparent kinetic constants were estimated. A role for ADH in the catabolism of L-alanine to pyruvate during vegetative growth on L-alanine and during sporulation of cells cultured on glucose is proposed on the basis of these experimental results. 59()on July 31, 2020 by guest

Metabolic role and regulation of ?-alanine dehydrogenase in Rhodopseudomonas capsulata

“…L-Alanine dehydrogenase (ADH, EC 1.4.1.1) is a key enzyme in the catabolism of L-alanine [1][2][3]. It has been suggested that, under conditions with high external ammonia concentrations, ADH activity could also account for NH + -assimilation in organisms lacking glutamate dehydrogenase (EC 1.4.1.2), as for example, Bacillus species [4], bluegreen bacteria [5] and the facultative phototrophic bacterium, Rhodopseudomonas (Rps.)…”

Identification of Lysine 74 in the Pyruvate Binding Site of Alanine Dehydrogenase from Bacillus subtilis

“…In Bacillus species this enzyme is known to play a key role in the generation of pyruvate as energy source during sporulation (5,6). The kinetic properties of the enzyme have been elucidated (7), together with the mechanism (8) and the limiting steps of the catalysis (9).…”

Regulation of nitrogen catabolic enzymes in Vibrio alginolyticus

“…The Hut enzymes were assayed by using the methods of Lund and Magasanik [21] and Chasin and Magasanik [16], as described previously [17]. Alanine dehydrogenase was assayed by using the method of McCowen and Phibbs [22], and arginase by the method of Ratner [23]. One unit of alanine dehydrogenase and of arginase activity is defined as the amount of enzyme that gives an increase in absorbance of 0.1 at 340 and 515 nm, in 2.5 and 20 min and at 22 and 37°C, respectively.…”