title: 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) (l-alanine: 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 postlogarithmic-phase metabolism. Addition of 10 mM glucose to cultures during logarithmic-phase 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.
mesh_terms: D000409:Alanine / Q000378:metabolism; D000594:Amino Acid Oxidoreductases / Q000302:isolation & purification / Q000378:metabolism*; D000643:Ammonium Chloride / Q000378:metabolism; D000645:Ammonium Sulfate; D001407:Bacillus / Q000201:enzymology* / Q000254:growth & development / Q000378:metabolism; D002474:Cell-Free System; D011232:Chemical Precipitation; D002848:Chromatography, DEAE-Cellulose; D005947:Glucose / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D008293:Malates / Q000378:metabolism; D009243:NAD / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D011773:Pyruvates / Q000096:biosynthesis / Q000378:metabolism; D013053:Spectrophotometry; D013171:Spores, Bacterial / Q000254:growth & development; D013237:Stereoisomerism; D013997:Time Factors
chemical_list: D005971:Glutamates; D008293:Malates; D011773:Pyruvates; D000643:Ammonium Chloride; D009243:NAD; D009249:NADP; D000594:Amino Acid Oxidoreductases; D005947:Glucose; D000409:Alanine; D000645:Ammonium Sulfate