<i>Neisseria gonorrhoeae</i> and <i>Neisseria meningitidis</i> : Extracellular Enzyme Cleaves Human Immunoglobulin A

Abstract

The gonococcus and meningococcus, which infect human mucosal surfaces, elaborate a highly specific proteolytic enzyme which cleaves the immunoglobulin A1 subclass of the principal mucosal antibody, immunoglobulin A (IgA). The susceptible Pro-Thr bond lies in a unique region of the IgA heavy chain; the IgA2 subclass, lacking this peptide bond, is enzyme resistant.