Purification of staphylococcal coagulase.

Correlation between the pathogenicity of certain staphylococci and their ability to produce coagulase has led to extensive studies of the clotting enzyme. Walston (1935) precipitated the clotting substance from cell-free filtrates of appropriate staphylococcal cultures by the use of ethanol, acetic acid, or ammonium sulfate. Walker et al. (1948) partially purified staphylocoagulase by repeated precipitation at pH 4. Tager (1948) concentrated coagulase by acid treatment followed by several cycles of alcohol precipitation, alternating with the removal of impurities by the use of low concentrations of ammonium sulfate. Duthie and Lorenz (1952) obtained partially purified coagulase by cadmium sulfate fractionation. Aluminum oxide chromatography of such a preparation was described by Jacherts (1956). Recently, Duthie and Haughton (1958) isolated highly purified coagulase by adsorption onto cadmium sulfate, followed by fractional precipitation with ammonium sulfate at low pH values. Further purification of the clotting enzyme was attempted, to obtain a product for investigations of its role in the pathogenesis of staphylococcal infections.