Soluble NTPDase: An additional system of nucleotide hydrolysis in rat blood serum
| Autor: | Márcia Rosângela Wink, Jean Pierre Oses, Cristina Ribas Fürstenau, João José Freitas Sarkis, Renata Albuquerque Germano, Bárbara Rücker, Carla Denise Bonan, Ana Maria Oliveira Battastini, Cássia Maria Cardoso, Inajara Barreto Kirst |
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| Jazyk: | angličtina |
| Rok vydání: | 2004 |
| Předmět: |
Male
General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound Antigens CD ATP hydrolysis nucleotidases Animals Nucleotide Enzyme Inhibitors Rats Wistar General Pharmacology Toxicology and Pharmaceutics Adenosine Triphosphatases chemistry.chemical_classification Nucleotides Apyrase Hydrolysis Phosphodiesterase General Medicine Molecular biology Rats Enzyme Solubility chemistry Biochemistry Phosphodiesterase I adenosine Nucleoside triphosphate Thymidine Nucleoside serum |
| Zdroj: | Repositório Institucional PUCRS Pontifícia Universidade Católica do Rio Grande do Sul (PUCRS) instacron:PUC_RS |
| Popis: | The participation of a nucleoside triphosphate diphosphohydrolase in the nucleotide hydrolysis by rat blood serum was evaluated. Nucleoside triphosphate diphosphohydrolase and phosphodiesterase are enzymes possibly involved in ATP and ADP hydrolysis. The specific activity of the phosphodiesterase activity (using thymidine 5'-monophosphate p-nitrophenyl ester as substrate) was 4.92 +/- 0.73 (mean +/- SD, n = 10) nmol p-nitrophenol.min(-1).mg(-1) protein and the specific activities for ATP and ADP were 1.31 +/- 0.37 (mean +/- SD, n = 7) and 1.36 +/- 0.25 (mean +/- SD, n = 5) nmol Pi.min(-1).mg(-1) protein, respectively. A competition plot demonstrated that ATP and ADP hydrolysis occurs at the same active site. The effect of suramin and phenylalanine on ATP, ADP and thymidine 5'-monophosphate p-nitrophenyl ester hydrolysis was investigated. The results were opposite considering the hydrolysis of ATP and ADP and that of the substrate marker for the enzyme phosphodiesterase. These results are indicative of the presence of, at least, two enzymes participating in the serum nucleotide hydrolysis. The presence of cAMP did not affect the hydrolysis velocity of ATP and ADP, while thymidine 5'-monophosphate p-nitrophenyl ester hydrolysis was inhibited by cAMP by approximately 47%, suggesting that the hydrolysis of the ATP and ADP, under our assay conditions, occurs at a different site from the phosphodiesterase site. Both enzyme activities, in the rat blood serum, may be involved in the modulation of the nucleotide/nucleoside ratio in the circulation, serving an in vivo homeostatic and antithrombotic function. In addition, the phosphodiesterase may act on DNA or RNA liberated upon tissue injury and/or cell death. |
| Databáze: | OpenAIRE |
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