Na+/K+ - ATPase ACTIVITY IN NORMAL AND SICKLE CELL ERYTHROCYTES

Abstract

Na⁺/K⁺ - ATPase activity, was found to be highest in HbSS, followed by HbAS and then HbAA in all the samples analyzed. The enzyme activity was found to increase with increase in temperature and then optimum temperature was found to be 40^oC in all the genotypes. The enzyme was also found to obey hyperbolic kinetics. The Km of the enzyme was found to be 0.38mM, while the Vmax was 305.8 µmol Pi/Mg Pr/hr. The enzyme also had activation energy (Ea) of 0.14 Kcal/mol. The differences in the enzyme activity for the various genotypes tested would mean that the rate of Na⁺, K⁺ uptake by the active transport mechanism would be in the order, HbSS > HbAS > HbAA.

Keywords: Na⁺/K⁺ - ATPase, Enzyme, Genotypes, Activation Energy, Kinetics, Temperature, Vmax, Km.