[The action of proteolytic enzymes of Legionella pneumophila on human serum proteins (author's transl)].

The ability of proteolysis by four stains of L. pneumophila the etiologic agent of the Legionnaires' Disease was studied by the method of immunoelectrophoresis. 18 human serum proteins were tested as substrates (Table 1). Four proteins were degraded: alpha 1-acid glycoprotein (Fig. 1), alpha 1-antichymotrypsin (Fig. 2), beta-lipoprotein (Fig. 3), and beta 2-glycoprotein-I (Fig. 4). It can be suggested that the pathogenic action of L. pneumophila is due to that enzymatic activity, especially since alpha 1-acid glycoprotein, alpha 1-antichymotrypsin and beta 2-glycoprotein-I belong to the acute phase proteins and also beta-lipoprotein is involved in the unspecific resistance of the organism against infections.