title: Methylene reductase: responsible for the in vitro formation of formaldehyde from 5-methyltetrahydrofolic acid.
abstract: Formaldehyde formation from 5-methyltetrahydrofolic acid, as well as its further reaction with beta -phenylthanolamine to form a tetrahidroisoquinoline derivative, is activated in rat crude tissue extracts by the addition of menadione to the incubation mixtures. FAD also stimulates the process in the presence of oxygen, but fails to do so in the absence of the latter compound. Together, FAD and menadione maximally stimulate the formation of formaldehyde, or of the amine derivative, under anaerobic conditions. These properties of the "formaldehyde-forming enzyme" correlate to those previously reported for methylene reductase and strongly suggest that both enzyme activities are identical.
mesh_terms: D000332:Aerobiosis; D000693:Anaerobiosis; D000818:Animals; D001921:Brain / Q000201:enzymology; D055598:Chemical Phenomena; D002621:Chemistry; D005182:Flavin-Adenine Dinucleotide; D005557:Formaldehyde / Q000138:chemical synthesis*; D066298:In Vitro Techniques; D007668:Kidney / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D008297:Male; D010088:Oxidoreductases; D051381:Rats; D013763:Tetrahydrofolates
chemical_list: D013763:Tetrahydrofolates; D005182:Flavin-Adenine Dinucleotide; D005557:Formaldehyde; D010088:Oxidoreductases