Ecto-ATPase and ecto-ATP-diphosphohydrolase are co-localized in rat hippocampal and caudate nucleus synaptic plasma membranes

Title:

Ecto-ATPase and ecto-ATP-diphosphohydrolase are co-localized in rat hippocampal and caudate nucleus synaptic plasma membranes

Creator:

Nedeljkovic, N., Banjac, A., Horvat, A., Stojiljkovic, M., and Nikezic, G.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:97342760-97aa-406b-8b2b-b6cb07e4c08b
uuid:97342760-97aa-406b-8b2b-b6cb07e4c08b
issn:0862-8408

Subject:

Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, Ecto-ATPase, ecto-ATPhydroxylase, hippocampus, caudate nucleus, rat, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print, bez média, and svazek

Description:

Enzymes that hydrolyze extracellular ATP, i.e. ecto-ATPase and ecto-ATP diphosphohydrolase (ATPDase), can be differentiated by ability of the latter to hydrolyze ADP and by slightly different kinetic properties of the two enzymes. Synaptic plasma membrane fractions isolated from rat hippocampus and caudate nucleus exhibit ADP-hydrolyzing activity, as revealed by the enzyme assay, and the presence of ecto-ATPase protein, as revealed by immunological identification on Western blot. These findings indicate that both enzymes are co-expressed in the synaptic membrane compartment of hippocampal and caudate nucleus neurons. Kinetic analysis was performed to determine the relative contribution of each enzyme to the total ATP-hydrolyzing activity, while an inhibition study was carried out in order to exclude the interference of other nonspecific ATPase and phosphatase activities. Based on the kinetic properties, sensitivity to inhibitors and VATP/VADP ratio of about 2, we concluded that a substantial portion of ATP-hydrolyzing activity in both synaptic membrane preparations can be ascribed to the catalytic action of ATPDase. On the other hand, the highest catalytic efficacy when ATP is the substrate and the greater abundance of ecto-ATPase protein in caudate nucleus preparation suggest that the relative contribution of ecto-ATPase to the total ATP-hydrolyzing activity in the caudate nucleus is higher than in the hippocampus., N. Nedeljkovic, A. Banjac, A. Horvat, M. Stojiljkovic, G. Nikezic., and Obsahuje bibliografii

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2003 Volume:52 | Number:6

Harvested from:

CDK

Metadata only:

false