Trypanosoma spp., Leishmania spp. and Leptomonas spp.: Enzymes of ornithine-arginine metabolism

Eight species of trypanosomatid flagellates, Trypanosoma cruzi, T. mega, T. conorhini, Leishmania donovani, L. braziliensis, Leptomonas seymouri, L. collosoma, and L. samueli, were examined for the presence of enzymes of the arginine-ornithine metabolism. Arginase was found in species of the genera Leishmania and Leptomonas. Citrulline hydrolase was found only in species of Leptomonas. Trypanosoma spp. did not present any of the mentioned enzymes. Ornithine carbamoyltransferase and argininosuccinate lyase were found only in Leptomonas samueli, which also possessed arginine deiminase. With the sole exception of L. samueli the other species seem to present a uniform enzyme constitution, peculiar to their genera and different from the enzyme patterns of other genera of trypanosomatids already known. The potential usefulness of these findings for taxonomical purposes is discussed.