A novel ATP-Adpase from Mimosa pulvinus

1. 1. The ATPase of Mimosa pudica pulvinus hydrolyzed various nucleoside triphosphates, but the presence of divalent cations was required for obtaining positive activity. 2. 2. The enzyme also hydrolyzed the nucleoside diphosphates but it did not hydrolyze AMP, PPi or PNPP. 3. 3. On the basis of its activity with both triphosphates and diphosphates, quantitative relationships between ATP, ADP and AMP were traced by HPLC. 4. 4. The present enzyme did not hydrolyze ATP and ADP at the same time, but it first hydrolyzed the ADP rapidly and then the ATP rather slowly. 5. 5. The ATPase isolated from Mimosa pudica pulvinus is an ATP-ADPase of a type which differs from the known enzymes such as apyrase.