Mechanistic implications of the potassium-potassium exchange carried out by the sodium-potassium pump.
AUTOR(ES)
Sachs, J R
RESUMO
1. The magnitude of the K-K exchange carried out by the Na pump in human red cells was measured as a function of the external K concentration in cells with high and low intracellular K. The apparent K1/2 for external K and the Vm increased by the same proportion when intracellular K was raised. The result suggests that the K-K exchange is part of a ping-pong reaction mechanism. 2. The velocity of the exchange increases monotonically with intracellular phosphate and ATP concentration; neither substrate inhibits at very high concentration. 3. These results seem to require that the enzyme species which carries out the exchange is both phosphorylated and combined with ATP.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1248146Documentos Relacionados
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