Purification and properties of N5, N10-methylenetetrahydrofolate dehydrogenase of calf thymus
1965; Elsevier BV; Volume: 105; Issue: 2 Linguagem: Inglês
10.1016/s0926-6593(65)80152-7
ISSN1878-1454
AutoresYun‐Chi Yeh, David M. Greenberg,
Tópico(s)Metabolism and Genetic Disorders
ResumoSummary 1. 5,10-Methylenetetrahydrofolate:NADP-oxidoreductase (EC 1.5.1.5)1 from calf-thyxnus acetone-powder extracts has been purified about 100 fold. The enzyme is highly unstable, but can be partially protected against inactivation by thiol compounds (mercaptoethanol) and glycerol. 2. The substrates for the enzyme have been demonstrated to be d, L -methylene-tetrahydropteroylglutamate and NADP+. Tetrahydropteroyl- L -aspartate and tetra-hydropteroyltriglutamate were found to be as effective substrates as the mono-glutamate. Tetrahydropteroyl- D -glutamate and tetrahydropteroic acid were found to be completely inactive. 3. The dehydrogenation reaction has been shown to be reversible, but the equilibrium greatly favors the formation of N5, N10-methenyltetrahydrofolate. 4. A variety of chemical and kinetic properties of the enzyme have been determined.
Referência(s)