A New Type of Adenosinetriphosphatase from Dog Kidney

• Published in: Journal of biochemistry (Tokyo) 1969-03, Vol.65 (3), p.393-400
• Main Author: Suzuki, J
• Format: Article
• Language: English
• Subjects: Adenine Nucleotides; Adenosine Triphosphatases - isolation & purification; Animals; Ascorbic Acid; Calcium; Chemical Phenomena; Chemistry; Dogs; Hydrogen-Ion Concentration; Kidney - enzymology; Kinetics; Magnesium; Metals; Molecular Weight; Potassium; Renin; Sodium; Temperature; Thiamine Pyrophosphate
• ISSN: 0021-924X; 1756-2651
• DOI: 10.1093/oxfordjournals.jbchem.a129026

1. A new type of ATPase [EC 3.6.1., ATP phosphohydrolase] was extracted with 0.6 m KC1 from dog renal cortex and highly purified. The purified enzyme was stable and when assayed at pH5.6 (acetate buffer) and 37° in the presence of lmM ATP hydrolyzed 5.6μmoles of ATP into ADP and Pi/mg protein/min. 2. Neither Ca++ nor Mg++ was required for the enzyme activity; Na+, K+, Ca++, Mg++ and other metal ions were rather inhibitory. 3. The enzyme hydrolyzed all triphosphates tested and PP1. No monophosphates or diphosphates tested other than PPi were hydrolyzed. ADP and thiamine pyrophos-phatc were rather inhibitory. 4. The activity was inhibited by ascorbate. 5. The Km value of the ATPase for ATP was 2×10−4m. The value was not changed by the presence of ADP, but was raised to 2.5×10−4m in the presence of ascorbate and thiamine pyrophosphate. 6. The molecular weight of the enzyme was similar to that of renin [EC 3.4.4.15; 43, 000] which contaminated the ATPase preparation up to the middle step of the purification procedure.