title: Catabolite repression during single and multiple induction in Escherichia coli.
abstract: Intracellular concentration of cAMP regulates the synthesis of enzymes sensitive to catabolite repression. The relationship between the single and multiple induction of beta-galactosidase (EC 3.2.1.23), L-tryptophanase (EC 4.1.99.1), D-serine deaminase (EC 4.2.1.14), L-asparaginase (EC 3.5.1.1) and L-malate dehydrogenase (EC 1.1.1.37) was studied and the effect of cAMP level on the induction in Escherichia coli Crookes (ATCC 8739) was investigated. A varying degree of catabolite repression was observed during induction of individual enzymes induced separately on different energy sources. The synthesis of l-tryptophanase was most sensitive, whereas l-asparaginase was not influenced at all. Exogenous cAMP was found to overcome partially the catabolite repression of beta-galactosidase and D-serine deaminase, both during single induction. The synthesis of l-malate dehydrogenase was negatively influenced by the multiple induction even in the presence of cAMP; on the other hand, the synthesis of l-tryptophanase was stimulated, independently of the level of the exogenous cAMP. Similarly, the activity of L-asparaginase slightly but significantly increased during the multiple induction of all five enzymes; here too the activity increase did not depend on exogenous cAMP.
mesh_terms: D001215:Asparaginase / Q000096:biosynthesis; D000242:Cyclic AMP / Q000494:pharmacology*; D004790:Enzyme Induction / Q000187:drug effects; D004794:Enzyme Repression / Q000187:drug effects; D004926:Escherichia coli / Q000201:enzymology*; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D012695:L-Serine Dehydratase / Q000096:biosynthesis; D008291:Malate Dehydrogenase / Q000096:biosynthesis; D014368:Tryptophanase / Q000096:biosynthesis; D001616:beta-Galactosidase / Q000096:biosynthesis
chemical_list: D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D000242:Cyclic AMP; D008291:Malate Dehydrogenase; D001616:beta-Galactosidase; D001215:Asparaginase; D014368:Tryptophanase; D012695:L-Serine Dehydratase