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Interactions of nicotinamide-adenine dinucleotide phosphate analogues and fragments with pigeon liver malic enzyme. Synergistic effect between the nicotinamide and adenine moieties.
| Content Provider | Semantic Scholar |
|---|---|
| Author | Chang, G. G. |
| Copyright Year | 1987 |
| Abstract | The structural requirements of the NADP+ molecule as a coenzyme in the oxidative decarboxylation reaction catalysed by pigeon liver malic enzyme were studied by kinetic and fluorimetric analyses with various NADP+ analogues and fragments. The substrate L-malate had little effect on the nucleotide binding. Etheno-NADP+, 3-acetylpyridine-adenine dinucleotide phosphate, and nicotinamide-hypoxanthine dinucleotide phosphate act as alternative coenzymes for the enzyme. Their kinetic parameters were similar to that of NADP+. Thionicotinamide-adenine dinucleotide phosphate, 3-aminopyridine-adenine dinucleotide phosphate, 5'-adenylyl imidodiphosphate, nicotinamide-adenine dinucleotide 3'-phosphate and NAD+ act as inhibitors for the enzyme. The first two were competitive with respect to NADP+ and non-competitive with respect to L-malate; the other inhibitors were non-competitive with NADP+. All NADP+ fragments were inhibitory to the enzyme, with a wide range of affinity, depending on the presence or absence of a 2'-phosphate group. Compounds with this group bind to the enzyme 2-3 orders of magnitude more tightly than those without this group. Only compounds with this group were competitive inhibitors with respect to NADP+. We conclude that the 2'-phosphate group is crucial for the nucleotide binding of this enzyme, whereas the carboxyamide carbonyl group of the nicotinamide moiety is important for the coenzyme activity. There is a strong synergistic effect between the binding of the nicotinamide and adenosine moieties of the nucleotide molecule. |
| File Format | PDF HTM / HTML |
| DOI | 10.1042/bj2450407 |
| PubMed reference number | 3663167 |
| Journal | Medline |
| Volume Number | 245 |
| Issue Number | 2 |
| Alternate Webpage(s) | http://www.biochemj.org/content/ppbiochemj/245/2/407.full.pdf |
| Alternate Webpage(s) | https://doi.org/10.1042/bj2450407 |
| Journal | The Biochemical journal |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
