Coagulase: The production and mode of action of the plasma-clotting enzyme of Staphylococcus aureus

Any work on the synthesis of bacterial enzymes is faced at the outset by the truth embodied in the aphorism of Maurice Nicolle in his teaching at the Pasteur Institute: "The bacterial cell is a mosaic of antigens and enzymes". The pattern is so intricate even within a single species that any one investigator can hope to throw only a little light on a minute corner of this mosaic. In the work that forms the subject matter of this thesis interest is concentrated on a single enzyme, coagulase, of a single bacterial species, Staphylococcus aureus. There are many reasons for choosing to investigate this particular enzyme. Most bacterial enzymes are common to a large number of species - coagulase is unique. It is produced only by Staph. Aureus. Most bacterial enzymes act as small links in long chains of metabolic reactions - coagulase appears to have only one function, the clotting of animal plasm. Most bacterial enzymes are elaborated in an inactive state and requires for activation the intervention of a factor present in the plasm of animals. Finally, an additional interest attaches to this enzyme from the increasing emphasis now being placed on its role in establishing staphylococcal infections. For these reasons it was decided to investigate conditions governing the formation and mode of action of coagulase, the plasm-clotting enzyme of Staph. Aureus. The investigations fell into three main divisions: (1) factors affecting coagulase production in laboratory media, (2) factors affecting coagulase production in chemically defined media, and (3) the nature of the reaction by which coagulase is converted to its active form. The work on coagulase production in chemically defined media and in laboratory media was done partly in collaboration with other members of the Department of Bacteriology. The work on the conversion of coagulase to active coagulase was done entirely in collaboration