Adenosine Triphosphatase in Isolated Membranes ofStaphylococcus aureus

Publisher Website
Google Scholar
Abstract
The preparation of cytoplasmic membranes from suspensions ofStaphylococcus aureuslysed by an enzyme recently isolated in these laboratories is described. These membranes contained: protein, 34.4%; ribonucleic acid, 6.6%; lipids, 34.5%; and total phosphorus, 1.4%. Such membranes exhibited adenosine 5′-triphosphatase (E.C. 3.6.1.3) activity, liberating orthophosphate at an initial rate of 0.53 μmole per min per mg of protein under optimal conditions. The enzyme was Mg++-dependent and K+- or Na+-stimulated. Maximal activity was observed with a molar adenosine 5′-triphosphate (ATP) to Mg++ratio of 1. One mole of orthophosphate was liberated per mole of ATP; the other product of digestion was adenosine 5′-diphosphate. Inorganic pyrophosphate and the 5′-triphosphates of guanosine, uridine, and cytidine were also attacked by membrane preparations, but more slowly than ATP. Ouabain,p-chloromercuribenzoate, and 2,4-dinitrophenol did not alter adenosine triphosphatase activity, whereas both Atebrine and chlorpromazine were inhibitory.

This publication has 24 references indexed in Scilit: