title: CO2-fixing enzymes in Pseudomonas fluorescens.
abstract: Pseudomonas fluorescens grown on glucose or glutamate at 1 or 20 degrees C, or on acetate at 20 degrees C, as sole carbon sources, contained both pyruvate carboxylase and phosphoenolpyruvate carboxylase. Pyruvate carboxylase was insensitive to acetyl-coenzyme A and L-aspartate, and its level in cell-free extracts was markedly dependent on the carbon source for growth, the highest specific activity being attained in glucose-grown cells. Phosphoenolpyruvate carboxylase, on the other hand, although less dependent on the nature of the carbon source,showed its highest level in acetate-grown cells; the enzyme activity required acetyl-coenzyme A and was strongly inhibited by L-aspartate. The micro-organism had, in addition, a phosphoenolpyruvate carboxykinase, which showed its highest specific activity in cells grown on acetate, and a NADP-linked malate enzyme, apparently repressed by acetate and showing its highest specific activity in glutamate-grown cells.
mesh_terms: D000085:Acetates / Q000378:metabolism; D000105:Acetyl Coenzyme A / Q000494:pharmacology; D001224:Aspartic Acid / Q000494:pharmacology; D002245:Carbon Dioxide / Q000378:metabolism; D002262:Carboxy-Lyases / Q000378:metabolism*; D002474:Cell-Free System; D004794:Enzyme Repression; D005947:Glucose / Q000378:metabolism; D005971:Glutamates / Q000378:metabolism; D008291:Malate Dehydrogenase / Q000378:metabolism*; D010729:Phosphoenolpyruvate Carboxykinase (GTP) / Q000378:metabolism*; D011551:Pseudomonas fluorescens / Q000201:enzymology* / Q000378:metabolism; D011766:Pyruvate Carboxylase / Q000378:metabolism*; D013696:Temperature
chemical_list: D000085:Acetates; D005971:Glutamates; D002245:Carbon Dioxide; D001224:Aspartic Acid; D000105:Acetyl Coenzyme A; D008291:Malate Dehydrogenase; D002262:Carboxy-Lyases; D010729:Phosphoenolpyruvate Carboxykinase (GTP); D011766:Pyruvate Carboxylase; D005947:Glucose