Co-purification of three folate enzymes from porcine liver

Abstract

Three folate enzymes, 5,10-methylenetetrahydrofolate dehydrogenase, 5,10-methenyltetrahydrofolate cyclohydrolase, and 10-formyltetrahydrofolate synthetase have been purified 100-fold from porcine liver. The three activities co-purify through fractionation with (NH 4) 2SO 4, polyethylene glycol-6000, and chromatography on DEAE-Sephadex and phosphocellulose columns. In addition, the observation that NADP, a substrate for the dehydrogenase, protects all three enzymes from heat inactivation suggests that the enzymes are present as a protein complex.