Biosynthesis of Polyamines in Phytomonas sp: involvement of ODC and ADC pathways

CEJAS S; CARRILLO C; GONZÁLEZ NS; ALGRANATI ID

Caxambú, Brazil

Congreso; XXVIII Reunião Anual de Pesquisa em Doença de Chagas e XVII Reunião Anual de Protozoologia; 2001

Phytomonas is a flagellated which parasites plants, causing lethal diseases in species of economical interest. Polyamine metabolism is a potential target for development of antiparasitic strategies. In this work we have demonstrated that promastigote forms of Phytomonas, TCC066, contains ornithine decarboxylase (ODC) activity, the first enzyme in the synthesis of polyamines. This enzyme showed a half-life of 1 hour. DFMO, the specific ODC inhibitor, inhibited the enzyme and the production of polyamines and slowed down the parasite proliferation transiently, with a subsequent recovery of the growth rate. The addition of CHA, specific inhibitor of spermidine synthase, arrested the parasite proliferation. On the other hand, ADC activity, the alternative pathway to polyamines, was not detected in this parasite: although a great arginine decarboxylation was observed, this activity was not inhibited by the specific ADC inhibitor DFMA and neither agmatine nor putrescine were produced.