dc.creator | POCHMANN, Daniela | |
dc.creator | INNOCENTE, Adrine M. | |
dc.creator | COTOMACCI, Guilherme | |
dc.creator | BARRETO-CHAVES, Maria Luiza M. | |
dc.creator | SARKIS, Joao J. F. | |
dc.date.accessioned | 2012-10-20T03:16:36Z | |
dc.date.accessioned | 2018-07-04T15:33:58Z | |
dc.date.available | 2012-10-20T03:16:36Z | |
dc.date.available | 2018-07-04T15:33:58Z | |
dc.date.created | 2012-10-20T03:16:36Z | |
dc.date.issued | 2008 | |
dc.identifier | BIOSCIENCE REPORTS, v.28, n.5, p.267-273, 2008 | |
dc.identifier | 0144-8463 | |
dc.identifier | http://producao.usp.br/handle/BDPI/27876 | |
dc.identifier | 10.1042/BSR20070039 | |
dc.identifier | http://dx.doi.org/10.1042/BSR20070039 | |
dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/1624520 | |
dc.description.abstract | The present study describes the enzymatic properties and molecular identification of 5`-nucleotidase in soluble and microsomal fractions from rat cardiac ventricles. Using AMP as a substrate, the results showed that the cation and the concentration required for maximal activity in the two fractions was magnesium at a final concentration of 1 mM. The pH optimum for both fractions was 9.5. The apparent K-m (Michaelis constant) values calculated from the Eadie-Hofstee plot were 59.7 +/- 10.4 mu M and 134.8 +/- 32.1 mu M, with V-max values of 6.7 +/- 0.4 and 143.8 +/- 23.8 nmol P-i/min/mg of protein (means +/- S.D., n = 4) from soluble and microsomal fractions respectively. Western blotting analysis of ecto-5`-nucleotidase revealed a 70 kDa protein in both fractions, with the major proportion present in the microsomal fraction. The presence of these enzymes in the heart probably has a physiological function in adenosine signalling. Furthermore, the presence of ecto-5`-nucleotidase in the microsomal fraction could have a role in the modulation of the excitation-contraction-coupling process through involvement of the Ca2+ influx into the sarcoplasmic reticulum. The measurement of maximal enzyme activities in the two fractions highlights the potential capacity of the different pathways of purine metabolism in the heart. | |
dc.language | eng | |
dc.publisher | PORTLAND PRESS LTD | |
dc.relation | Bioscience Reports | |
dc.rights | Copyright PORTLAND PRESS LTD | |
dc.rights | closedAccess | |
dc.subject | adenosine | |
dc.subject | AMP hydrolysis | |
dc.subject | ecto-5 `-nucleotidase | |
dc.subject | heart | |
dc.subject | microsome | |
dc.subject | soluble 5 `-nucleotidase | |
dc.title | AMP hydrolysis in soluble and microsomal rat cardiac cell fractions: kinetic characterization and molecular identification of 5 `-nucleotidase | |
dc.type | Artículos de revistas | |