title: Purification and properties of dihydrofolate reductase from cultured mammalian cells.
abstract: Dihydrofolate reductase was purified quickly and simply from small quantities of cultured mammalian cells by affinity chromatography. On gel electrophoresis of the purified enzyme, multiple bands of activity resulted from enzyme-buffer interaction at low but not high buffer concentration. A Ferguson plot (Ferguson, 1964) showed that this heterogeneity was due to a charge difference with no alteration in the size of the enzyme. Stimulation of enzyme activity by KCl, urea and p-hydroxymercuribenzoate, and inhibition by methotrexate and trimethoprim, showed only minor differences between the various enzymes.
mesh_terms: D002460:Cell Line; D002478:Cells, Cultured; D002846:Chromatography, Affinity; D004591:Electrophoresis, Polyacrylamide Gel; D005493:Folic Acid Antagonists; D006801:Humans; D006863:Hydrogen-Ion Concentration; D006902:Hydroxymercuribenzoates; D007700:Kinetics; D008727:Methotrexate / Q000494:pharmacology; D008970:Molecular Weight; D011134:Polysaccharides; D011189:Potassium Chloride / Q000494:pharmacology; D013056:Spectrophotometry, Ultraviolet; D013762:Tetrahydrofolate Dehydrogenase / Q000302:isolation & purification* / Q000378:metabolism; D014295:Trimethoprim / Q000494:pharmacology; D014508:Urea / Q000494:pharmacology
chemical_list: D005493:Folic Acid Antagonists; D006902:Hydroxymercuribenzoates; D011134:Polysaccharides; D011189:Potassium Chloride; D014508:Urea; D014295:Trimethoprim; D013762:Tetrahydrofolate Dehydrogenase; D008727:Methotrexate