Biochemical properties of Candida parapsilosis ecto-5'-nucleotidase and the possible role of adenosine in macrophage interaction |
| |
Authors: | Russo-Abrahão Thais Cosentino-Gomes Daniela Gomes Marta T Alviano Daniela S Alviano Celuta S Lopes Angela H Meyer-Fernandes José Roberto |
| |
Institution: | Instituto de Bioquímica Médica, Centro de Ciências da Saúde, Universidade Federal do Rio de Janeiro, UFRJ, Cidade Universitária, Rio de Janeiro, RJ, Brazil. |
| |
Abstract: | Candida parapsilosis is considered to be an emerging fungal pathogen because it is associated with an increasing range of infections. In this work, we biochemically characterized ecto-5'-nucleotidase activity on the surface of living, intact C. parapsilosis cells. At a pH of 4.5, intact cells were able to hydrolyze 5'-AMP at a rate of 52.44 ± 7.01 nmol Pi h(-1) 10(-7) cells. 5'-AMP, 5'-IMP and 5'-UMP were hydrolyzed at similar rates, whereas 5'-GMP and 5'-CMP hydrolyzed at lower rates. Enzyme activity was increased by about 42% with addition of Mg(2+) or Ca(2+), and the optimum pH was in the acidic range. An inhibitor of phosphatase activities, sodium orthovanadate, showed no effect on AMP hydrolysis; however, as expected, ammonium molybdate, a classical nucleotidase inhibitor, inhibited the activity in a dose-dependent manner. The results indicated that the existence of an ecto-5'-nucleotidase could play a role in the control of extracellular nucleotide concentrations. |
| |
Keywords: | |
本文献已被 PubMed 等数据库收录! |
|