title: Calmodulin and Ca2+-dependent cyclic AMP phosphodiesterase activity in Trypanosoma cruzi.
abstract: Calmodulin has been purified from Trypanosoma cruzi epimastigote forms by ion-exchange chromatography, gel filtration and affinity chromatography on 2-chloro-10-(3-aminopropyl)phenotiazine-Sepharose. Upon sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the factor showed a polypeptide band with an apparent molecular weight of 16 000. In addition, cyclic AMP phosphodiesterase activity from T. cruzi epimastigote forms was purified by ion-exchange chromatography and affinity chromatography on a brain calmodulin-Sepharose column. The enzyme was activated by homologous calmodulin as well as by bovine brain and Neurospora crassa calmodulins. The activation required micromolar concentrations of Ca2+ and it was blocked by EGTA and by some neuroleptic drugs such as chlorpromazine, fluphenazine and compound 48/80. Activations were observed at micromolar concentrations of cyclic AMP as substrate. In addition, T. cruzi calmodulin was also active in bringing about the stimulation of brain phosphodiesterase.
mesh_terms: D015105:3',5'-Cyclic-AMP Phosphodiesterases / Q000302:isolation & purification / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000494:pharmacology*; D002147:Calmodulin / Q000302:isolation & purification / Q000494:pharmacology*; D002417:Cattle; D002540:Cerebral Cortex / Q000201:enzymology; D007700:Kinetics; D009492:Neurospora crassa / Q000378:metabolism; D014349:Trypanosoma cruzi / Q000201:enzymology*
chemical_list: D002147:Calmodulin; D015105:3',5'-Cyclic-AMP Phosphodiesterases; D002118:Calcium