Nucleoside phosphotransferase activity of human colon carcinoma cytosolic 5'-nucleotidase
| Autor: | Marcella Camici, Pl Ipata, Maria Grazia Tozzi, Francesco Sgarrella, Simone Allegrini, Rossana Pesi |
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| Rok vydání: | 1991 |
| Předmět: |
Inosine monophosphate
Nucleoside phosphotransferase activity Biophysics Guanosine Monophosphate Biology Biochemistry 5'-nucleotidase Phosphates chemistry.chemical_compound Adenosine Triphosphate Cytosol Inosine Monophosphate Nucleotidase Guanosine monophosphate Nucleoside phosphotransferase medicine Humans Inosine Molecular Biology 5'-Nucleotidase 2 3-Diphosphoglycerate Phosphotransferases Diphosphoglyceric Acids Molecular biology Kinetics chemistry Colonic Neoplasms Nucleoside medicine.drug |
| Zdroj: | Archives of biochemistry and biophysics. 291(2) |
| ISSN: | 0003-9861 |
| Popis: | A cytosolic 5'-nucleotidase, acting preferentially on IMP and GMP, has been isolated from human colon carcinoma extracts. This enzyme activity catalyzes also the transfer of the phosphate group of 5'-nucleoside monophosphates (mainly, 5'-IMP, 5'-GMP, and their deoxycounterparts) to nucleosides (preferentially inosine and deoxyinosine, but also nucleoside analogs, such as 8-azaguanosine and 2',3'-dideoxyinosine). It has been proposed that the enzyme mechanism involves the formation of a phosphorylated enzyme as an intermediate which can transfer the phosphate group either to water or to the nucleoside. The enzyme is activated by some effectors, such as ATP and 2,3-diphosphoglycerate. Results indicate that the effect of these activators is mainly to favor the transfer of the phosphate of the phosphorylated intermediate to the nucleoside (i.e., the nucleoside phosphotransferase activity). This finding is in accordance with previous suggestions that cytosolic 5'-nucleotidase cannot be considered a pure catabolic enzyme. |
| Databáze: | OpenAIRE |
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