Proteolytic action of Legionella pneumophila on human serum proteins

Abstract

Proteolysis by four strains of Legionella pneumophila, the etiological agent of Legionnaires disease, was studied by the method of immunoelectrophoresis. Twenty-three human serum proteins were tested as substrates. Five proteins were degraded: alpha 1-acid glycoprotein, alpha 1-antichymotrypsin, beta-lipoprotein, beta 1E-globulin, and beta 2-glycoprotein-I. Moreover, the degradation of alpha 1-antichymotrypsin was demonstrated by investigation of an enzyme-blocking test. It is suggested that the proteolytic activity of L. pneumophila may bear some relationship to its pathogenic activity.