title: The occurrence of cyclic AMP in aging cultures of the fungus Aspergillus ornatus.
abstract: The presence of endogenous cAMP was demonstrated in mycelial mats of Aspergillus ornatus Raper grown on cellulose xanthate membranes overlying a defined agar medium. Using a competitive binding assay cAMP was detected in 30 separate samples. Purification techniques increased the apparent cAMP concentration in excess of eight times the level observed in crude extracts. Cyclic AMP was only slightly detectable in extracts treated with phosphodiesterase. The concentration of endogenous cAMP as measured in purified extracts declined by approximately 60% in non-growing aging mycelial mats. Although there is an apparent age-related decline in endogenous cAMP levels and the activity of the tryptophan inducible enzyme, 2,3-dihydroxybenzoic acid carboxylyase (EC 4.1.1.46), (OPCA carboxylyase), the addition of 10(-3) M cAMP and/or 0.1% tryptophan to the culture medium did not increase OPCA carboxylyase activity in the fungus.
mesh_terms: D001230:Aspergillus / Q000254:growth & development / Q000378:metabolism*; D002262:Carboxy-Lyases / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism* / Q000494:pharmacology; D004790:Enzyme Induction / Q000187:drug effects; D013997:Time Factors; D014364:Tryptophan / Q000494:pharmacology
chemical_list: D014364:Tryptophan; D000242:Cyclic AMP; D002262:Carboxy-Lyases; C022501:2-pyrocatechuate decarboxylase