Glutamate formyl- and formimino-transferase activities from pig liver.
Formylglutamate:tetrahydrofolate formyltransferase (EC 2.1.2.6) from pig liver is not a separate entity, but represents a reaction catalyzed slowly by the active sites of formiminoglutamate:tetrahydrofolate formiminotransferase (EC 2.1.2.5). The two activities copurify through the stage of crystallization of the formiminotransferase and show very similar responses to heat inactivation and modification with diethylpyrocarbonate. Formylglutamate is a competitive inhibitor against formiminoglutamate, while glutamate is competitive against both the N-substituted glutamate substrates with similar values of Ki. Formyltransferase is a low activity with a Vmax of approximately 0.03% that of the formiminotransferase. All of the formyltransferase activity in liver extracts can be accounted for by the formiminotransferase enzyme.
D000818:Animals; D051042:Glutamate Formimidoyltransferase; D019877:Hydroxymethyl and Formyl Transferases; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D013379:Substrate Specificity; D013552:Swine; D014166:Transferases / Q000302:isolation & purification / Q000378:metabolism*
D014166:Transferases; D019877:Hydroxymethyl and Formyl Transferases; D051042:Glutamate Formimidoyltransferase