title: Involvement of tetrahydrofolate cofactors in de novo purine ribonucleotide synthesis by adult Brugia pahangi and Dirofilaria immitis.
abstract: Adult Brugia pahangi in vitro, unlike mouse leukemia L1210 cells, converted 5-methyltetrahydrofolate (CH3FH4) directly to 5,10-methylenetetrahydrofolate and thence to other FH4 cofactors. The excreted CO2 that was derived from CH3FH4 was due to the presence within the filariae of 10-formyltetrahydrofolate dehydrogenase (EC 1.5.1.6) which catalyzes the deformylation of 10-formyl-tetrahydrofolate. Adult B. pahangi and Dirofilaria immitis, incubated in a purine-free medium containing [5-14C]CH3FH4 as the only form of folate, synthesized purine ribonucleotides radiolabeled at positions 2 and 8 of the purine ring. Presumably, 10-formyl[14C]FH4 donated Carbon 2 during the synthesis de novo of the purine ring and 5,10-methenyl[14C]FH4 donated Carbon 8.
mesh_terms: D002009:Brugia / Q000032:analysis / Q000378:metabolism*; D002247:Carbon Isotopes / Q000032:analysis; D004182:Dirofilaria / Q000378:metabolism*; D005370:Filarioidea / Q000378:metabolism*; D005575:Formyltetrahydrofolates / Q000378:metabolism; D000587:Oxidoreductases Acting on CH-NH Group Donors / Q000378:metabolism; D011685:Purine Nucleotides / Q000032:analysis / Q000096:biosynthesis*; D012265:Ribonucleotides / Q000032:analysis / Q000096:biosynthesis*; D013763:Tetrahydrofolates / Q000032:analysis / Q000378:metabolism / Q000494:pharmacology*; D000099295:Formyltetrahydrofolate Dehydrogenase
chemical_list: D002247:Carbon Isotopes; D005575:Formyltetrahydrofolates; D000587:Oxidoreductases Acting on CH-NH Group Donors; D011685:Purine Nucleotides; D012265:Ribonucleotides; D013763:Tetrahydrofolates; D000099295:Formyltetrahydrofolate Dehydrogenase; C005984:5-methyltetrahydrofolate