Formation of 10-formylfolic acid, a potent inhibitor of dihydrofolate reductase, in rat liver slices incubated with folic acid.
During investigation of folate polyglutamate biosynthesis in rat liver slices utilizing [2-(14)C]folic acid, a folate compound that behaved like a polyglutamate form in the Sephadex G-15 gel filtration system was found to accumulate. Subsequent chromatographic, spectral, chemical, and enzymic studies have indicated that the compound formed in liver slices incubated with [(14)C]folic acid with and without methotrexate was 10-formyl folate. This folate is of interest in that it is the most potent natural inhibitor of dihydrofolate reductase known and may be capable of serving a regulatory function within the cell.
D000818:Animals; D002250:Carbon Radioisotopes; D002268:Carboxypeptidases / Q000378:metabolism; D002848:Chromatography, DEAE-Cellulose; D002850:Chromatography, Gel; D003067:Coenzymes; D005492:Folic Acid / Q000378:metabolism*; D005493:Folic Acid Antagonists; D005561:Formates / Q000378:metabolism*; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
D002250:Carbon Radioisotopes; D003067:Coenzymes; D005493:Folic Acid Antagonists; D005561:Formates; D005492:Folic Acid; D002268:Carboxypeptidases