Adenosine Triphosphatase of the Intracellular Particles of Aspergillus Oryzae*

Abstract

In 1951 Kielley and Kielley (1) reported that in rat liver mitochondria prepared in isotonic sucrose there is an increase in adenosine triphosphatase activity (ATP-ase) during incubation which is related to the decrease in oxidative phosphorylation. Since the decrease of oxidative phosphorylation was prevented by addition of adenylic compounds, they assumed that the ageing caused loss of some energy-rich components which are necessary for phosphorylation and thus ATP-ase appeared even in undamaged mitochondria. Furthermore Harman et al. (2) observed that morphological changes (swelling) of mitochondria of pigeon skeletal muscle are attended by an increase in ATP-ase activity. Mitochondria prepared in isotonic sucrose swell in hypotonic sucrose, and the swelling is promoted by addition of bivalent cations such as magnesium and calcium, and also by uncouplers of oxidative phosphorylation (3). In filamentous fungi, there is little information available on the morphology and physiology of the intracellular particles. This paper presents the results of studies on the ATP-ase of particles from Aspergillus oryzae.