K+-p-nitrophenylphosphatase activity in rat brain and liver.
| Autor: | Ďurfinová, Monika |
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| Další autoři: |
Líška, Branislav, 1943-
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| Jazyk: | angličtina |
| Předmět: | |
| Druh dokumentu: | Non-fiction |
| Abstrakt: | Abstract: K+-p-nitrophenylphosphatase (K+pNPPase) is the enzyme, which is considered to be involved in K+-dependent hydrolysis of the phosphoenzyme in the reaction cycle of Na+, K+-ATPase. The aim of our present study was to characterize some features of K+pNPPase in homogenates of the rat brain and liver. We determined p-nitrophenylphosphatase (pNPPase) activity in the presence of various ion combinations (Mg 2++K+, Mg2+, K+). We found a higher total pNPPase activity in the brain (0.8±0.079 nkat/mg protein) than in the liver (0.08±0.01 nkat/mg protein). Contrary to the liver, the main part of the total brain activity was K+-dependent. The activity of K+pNPPase was significantly higher in cerebral cortex homogenates (0.86±0.073 nkat/mg protein) in comparison to those of the whole brain (0.57±0.075 nkat/mg protein). The specific K+pNPPase activity was two times higher in the isolated pellet fraction (0.911±0.07 nkat/mg protein), rich in synaptosomes, compared to the whole brain homogenate (0.57±0.075 nkat/mg protein). Our results demonstrate the high activity of K+pNPPase in the brain tissue and its distribution mainly into the pellet fraction, what might indicate a possible role of K+pNPPase in specific structures of the brain, e.g. in synaptosomes. |
| Databáze: | Katalog Knihovny AV ČR |
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