PURIFICATION AND CHARACTERIZATION OF ADENOSINE-TRIPHOSPHATASE FROM EEL LIVER-MITOCHONDRIA

1. F1-ATPase has been purified from the liver mitochondria of eel (Anguilla anguilla). 2. The cold inactivation rate of the enzyme is low as compared to the F1-ATPases from other mitochondrial sources. 3. The capillary electrophoresis analysis of the native enzyme shows a single protein band. 4. The enzyme preparation comprises five polypeptides of mol. wt 55,000, 51,000, 32,000, 17,000, 8000 with a stoichiometry of 3:3:1:1:1 as estimated by the SDS-PAGE method. 5. F1-ATPase from eel liver mitochondria hydrolyses Mg-ATP with co-operative kinetics characterized by apparent K(m) values of 0.060 and 0.510 mM, and V(m) values of 3.6 and 11.4 U/mg. 6. The enzyme activity is pH-dependent with an optimum at pH 8.5 as observed for mammalian F1-ATPases. 7. The similarity of molecular and kinetic properties among F1-ATPases is discussed.