Evidence for a physiologically active nicotinamide phosphoribosyl transferase in cultured human fibroblasts
| Autor: | Martin Rechsteiner, G. C. Elliott |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Niacinamide
Biophysics Nicotinamide phosphoribosyltransferase Phosphoribosyl Pyrophosphate Nicotinamide adenine dinucleotide Biochemistry chemistry.chemical_compound Adenosine Triphosphate Humans Pentosyltransferases Nicotinamide Phosphoribosyltransferase Molecular Biology Cells Cultured Nicotinamide mononucleotide chemistry.chemical_classification biology Nicotinamide Cell Biology Fibroblasts NAD Molecular biology Enzyme assay Kinetics Enzyme chemistry biology.protein NAD+ kinase Adenosine triphosphate |
| Zdroj: | Biochemical and Biophysical Research Communications. 104:996-1002 |
| ISSN: | 0006-291X |
| Popis: | Nicotinamide phosphoribosyltransferase, (EC 2.4.2.12) was examined in extracts of diploid human fibroblasts grown in culture. The enzyme was found to have an apparent Km for nicotinamide of 1.6 × 10−6M, to be specific for nicotinamide, stimulated by adenosine triphosphate (ATP) and inhibited by nicotinamide adenine dinucleotide (NAD). In these respects it is very similar to rat liver nicotinamide phosphoribosyltransferase but not like the enzyme previously observed in human tissue extracts which had a Km for nicotinamide of approximately 0.1 M and was insensitive to ATP. Discovery of this enzyme activity supports previous studies using radiolabeled nicotinamide which show that human fibroblasts can incorporate nicotinamide into NAD directly through nicotinamide mononucleotide. |
| Databáze: | OpenAIRE |
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