A re-examination of purine and pyrimidine synthesis in the three main forms of Trypanosoma cruzi

Abstract

1. 1. Purine and pyrimidine synthesis and salvage has been re-examined in blood trypomastigote. intracellular amastigote and culture epimastigote forms of Trypanosoma cruzi. 2. 2. All forms are unable to biosynthesize the purine ring de novo and are thus dependent on salvage. Bases are preferred to nucleosides; nucleotides appear not to be salvaged. Adenine and guanine nucleotides are readily interconvertible. 3. 3. Pyrimidines can be both biosynthesized de novo and salvaged, although in vivo. only the former is likely to be of significance. Both bases and nucleosides are readily salvaged; nucleotides are not utilized to a significant extent. Pyrimidine ribonucleotides are freely interconvertible. 4. 4. Purine salvage and pyrimidine synthesis are both potential targets for chemotherapy. 5. 5. No major differences in purine and pyrimidine metabolism in the three main forms of the parasite were detected.