Identification of N5,N10-methylene tetrahydrofolate reductase as the enzyme involved in the 5-methyl tetrahydrofolate-dependent formation of a β-carboline derivative of 5-hydroxytryptamine in human platelets
1976; Elsevier BV; Volume: 173; Issue: 2 Linguagem: Inglês
10.1016/0003-9861(76)90305-2
ISSN1096-0384
AutoresRobert D. Stebbins, Emanuel Meller, H Rosengarten, Arnold J. Friedhoff, Robert Silber,
Tópico(s)Analytical Chemistry and Chromatography
ResumoAn enzyme in human platelets or rat brain incubated with 5-methyl tetrahydrofolate (5MeH4folate) yields formaldehyde (4, 13), which will combine with biogenic amines to form β-carbolines (5) or tetrahydroisoquinolines. This activity was purified 500-fold from human platelets which are the main storage site for 5-hydroxytryptamine in man. This enzyme was identical to N5, N10-methylene tetrahydrofolate (N5,N10-methylene H4folate) reductase by the following criteria: (i) co-purification, (ii) heat denaturation, (iii) pH response, (iv) molecular weight, (5) cofactor requirements. A mechanism involving the enzymatic generation of formaldehyde followed by adduct formation with a biogenic amine is proposed.
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