Biochemical characterization of ecto-nucleotide pyrophosphatase/phosphodiesterase (E-NPP, E.C. 3.1.4.1) from rat heart left ventricle
| Autor: | Bárbara Rücker, Márcia Rosângela Wink, Towia A. Libermann, João José Freitas Sarkis, Manoela E. Almeida, Luiz F. Zerbini |
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| Rok vydání: | 2007 |
| Předmět: |
Male
Heart Ventricles Suramin Clinical Biochemistry Antineoplastic Agents Divalent Nitrophenols Hydrolysis chemistry.chemical_compound Thymidine Monophosphate medicine Animals Nucleotide RNA Messenger Enzyme Inhibitors Pyrophosphatases Rats Wistar Sodium Azide Molecular Biology chemistry.chemical_classification Phosphoric Diester Hydrolases Reverse Transcriptase Polymerase Chain Reaction Phosphodiesterase Cell Biology General Medicine Rats medicine.anatomical_structure Enzyme chemistry Biochemistry Ventricle Sodium azide Synaptosomes medicine.drug |
| Zdroj: | Molecular and Cellular Biochemistry. 306:247-254 |
| ISSN: | 1573-4919 0300-8177 |
| Popis: | In the present study we investigate the biochemical properties of the members of NPP family in synaptosomes prepared from rat heart left ventricles. Using p-nitrophenyl-5′-thymidine monophosphate (p-Nph-5′-TMP) as substrate for E-NPPs in rat cardiac synaptosomes, we observed an alkaline pH dependence, divalent cation dependence and the K M value corresponded to 91.42 ± 13.97 μM and the maximal velocity (V max ) value calculated was 63.79 ± 3.59 nmol p-nitrophenol released/min/mg of protein (mean ± SD, n = 4). Levamisole (1 mM), was ineffective as inhibitor of p-Nph-5′-TMP hydrolysis in pH 8.9 (optimum pH for the enzyme characterized). Suramin (0.25 mM) strongly reduced the hydrolysis of p-Nph-5′-TMP by about 46%. Sodium azide (10 and 20 mM) and gadolinium chloride (0.3 and 0.5 mM), E-NTPases inhibitors, had no effects on p-Nph-5′-TMP hydrolysis. RT-PCR analysis of left ventricle demonstrated the expression of NPP2 and NPP3 enzymes, but excluded the presence of NPP1 member. By quantitative real-time PCR we identified the NPP3 as the enzyme with the highest expression in rat left ventricle. The demonstration of the presence of the E-NPP family in cardiac system, suggest that these enzymes could contribute with the fine-tuning control of the nucleotide levels at the nerve terminal endings of left ventricles that are involved in several cardiac pathologies. |
| Databáze: | OpenAIRE |
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