5.10- Methylenetetrahydrofolate dehydrogenase

Bartoschek, S., Buurman, G., Thauer, R. K., Geierstanger, B. H., Weyrauch, J. P., Griesinger, C., Nilges, M., Hutter, M. C., Helms, V. (2001) Re-face stereospecificity of methylenetetrahy-dromethanopterin dehydrogenases and methylenetetrahydrofolate dehydrogenases is predetermined by intrinsic properties of the substrate. Chem Bio Chem, in press. 

Methylenetetrahydrofolate dehydrogenase (NADP+) [EC 1.5.1.5] catalyzes the reaction of 5,10-methylenetet-rahydrofolate with NADP+ to produce 5,10-methenylte-trahydrofolate and NADPH. 5,10-Methylenetetrahydrofolate dehydrogenase (NAD+) [EC 1.5.1.15] catalyzes the reaction of 5,10-methylenetetrahydrofolate with NAD+ to produce 5,10-methenyltetrahydrofolate and NADH. 

METHYLENETETRAHYDROFOLATE DEHYDROGENASE METHYLMALO-NATE-SEMIALDEHYDE DEHYDROGENASE... 

Grignani et al. (G14) studied several of the enzymes of folate metabolism in human epidermis—both normal and psoriatic. Increased levels of folate reductase were found in the psoriatic lesion, and further enzyme could be induced by treatment of the patients with amethopterin. By contrast, formate-activating enzyme, 5,10-methylenetetrahydrofolate dehydrogenase, serine hydroxylase, and cyclohydrolase were normal in the psoriatic lesion. Formiminotetrahydrofolate transferase could not be measured either in normal or psoriatic skin. The activities of the above enzymes as well as the absence of the transferase are similar to the findings for small bowel but not to other tissues studied. How these findings... 

Figure 44.1 Folate-mediated one carbon metabolism network. Enzymes and transport proteins are enclosed in rectangular boxes. AHCY S-adenosyDiomocys-teine hydrolase AICART 5-aminoimidazole carboxamide ribonucleotide transferase BHMT betaine homocysteine methyltransferase CBS cystathionine beta-synthase DHFR dihydrofolate reductase FR folate receptor FTCD formimidoyltransferase cyclodeaminase GART glycinamide ribonucleotide transformylase MATs (MATI/MATIII) adenosylmethionine transferase enzyme I/III MS methionine synthase MSR methionine synthase reductase MT methyltransferase MTHFD methylenetetrahydrofolate dehydrogenase MTHFR 5,10-methylenete-trahydrofolate reductase MTHFS 5,10-methylenetetrahydrofolate synthase. RFC reduced folate AdoMet 5-adenosylmethionine AdoHcy S-adenosylhomocysteine Hey homocysteine SHMT serine hydroxymethyltransferase TS thymidylate synthase.

Three enzyme activities present in this protein methylenetetrahydrofolate dehydrogenase ... 

Methylenetetrahydrofolate dehydrogenase (EC 1.5.1.15) Methylenetetrahy-drofolate dehydrogenase, which catalyzes the synthesis of methenyltetrahydro-folate [Eq. (8)], has been detected in soybean... 

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