Jarroll E L, Lindmark D G, Paolella P
J Parasitol. 1983 Oct;69(5):846-9.
The pyrimidine metabolism of Tritrichomonas foetus (KV 1) was studied using whole cells and cell homogenates. Pyrimidines and pyrimidine nucleosides were readily incorporated into nucleic acids. Orotate and aspartate were not incorporated into pyrimidine bases. Enzymes of the pyrimidine salvage pathway (i.e., thymidine and uridine phosphorylases and uridine kinase) were detected in trophozoite homogenates, but the activities of de novo pyrimidine synthesis enzymes (i.e., carbamoylphosphate synthase, aspartate transcarbamoylase, dihydroorotase and dihydroorotate dehydrogenase) were below the level of detection in these same homogenates. The evidence presented supports the proposal that T. foetus is incapable of synthesizing pyrimidines de novo but is capable of salvaging preformed pyrimidines and pyrimidine nucleosides from the growth medium and that enzymes of this parasite's pyrimidine salvage pathway are not organelle-associated.
利用全细胞和细胞匀浆研究了胎儿三毛滴虫（KV 1）的嘧啶代谢。嘧啶和嘧啶核苷很容易掺入核酸中。乳清酸和天冬氨酸未掺入嘧啶碱基中。在滋养体匀浆中检测到嘧啶补救途径的酶（即胸苷磷酸化酶、尿苷磷酸化酶和尿苷激酶），但在相同的匀浆中，从头合成嘧啶的酶（即氨甲酰磷酸合酶、天冬氨酸转氨甲酰酶、二氢乳清酸酶和二氢乳清酸脱氢酶）的活性低于检测水平。所提供的证据支持以下观点：胎儿三毛滴虫不能从头合成嘧啶，但能够从生长培养基中挽救预先形成的嘧啶和嘧啶核苷，并且该寄生虫的嘧啶补救途径的酶与细胞器无关。
