title: Metabolism of dihydroaminopterin and the influence of aminopterin and related derivatives on the metabolism of (-)-5-formyl-tetrahydrofolic acid in Pediococcus cerevisiae.
abstract: [3H]Dihydroaminopterin, but not [3H]methotrexate or [3H]aminopterin, was rapidly taken up by resting cell of Pediococcus cerevisiae and inhibited the uptake of (-)-5-formyl-tetrahydrofolic acid to more than 90% at a concentration of 25 muM. On the other hand 5-formyl-tetrahydrofolic acid inhibited the uptake of dihydroaminopterin to a similar extent. Dihydroaminopterin was metabolized by Pediococcus cerevisiae, but not by Lactobacillus casei, to a compound tentatively identified as dihydroaminopterin diglutamate. Methotrexate or aminopterin at a concentration of 25 muM did not inhibit the uptake of 5-formyl-tetrahydrofolic acid in Pediococcus cervisiae, but inhibited the conversion of this compound to polyglutamate forms almost completely at a level of 2.5 mu M.
mesh_terms: D000630:Aminopterin / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology*; D005493:Folic Acid Antagonists / Q000378:metabolism; D005575:Formyltetrahydrofolates / Q000378:metabolism*; D008727:Methotrexate / Q000031:analogs & derivatives; D010376:Pediococcus / Q000187:drug effects / Q000378:metabolism*; D013329:Structure-Activity Relationship; D013763:Tetrahydrofolates / Q000378:metabolism*
chemical_list: D005493:Folic Acid Antagonists; D005575:Formyltetrahydrofolates; D013763:Tetrahydrofolates; D000630:Aminopterin; D008727:Methotrexate