Biochemical evidence for the presence of arginine decarboxylase activity in Trypanosoma cruzi.

Trypanosoma cruzi was found to release 14CO2 from radiolabeled arginine, and this effect was inhibited by either DL-alpha-difluoromethylarginine or monofluoromethylagmatine, both specific inhibitors of arginine decarboxylase (ADC). Furthermore, agmatine, which can be derived metabolically only by ADC-mediated arginine decarboxylation, was produced when T. cruzi was incubated with radiolabeled arginine, and agmatine production was inhibited in the presence of DL-alpha-difluoromethylarginine. These results constitute direct biochemical evidence for the presence in T. cruzi of ADC, an enzyme that does not occur in mammalian cells.