LIMITED CLEAVAGE OF HUMAN IMMUNOGLOBULINS BY ELASTASE OF HUMAN NEUTROPHIL POLYMORPHONUCLEAR GRANULOCYTES - POSSIBLE MODULATOR OF IMMUNE-COMPLEX DISEASE

Abstract

Human polymorphonuclear lysosomal granules contain a neutral protease which is capable of digesting human immunoglobulins [Ig]. The protease is located in the azurophil granules and enzymatically cleaves IgG, producing a Fab-like piece which is recoverable. The Fc-like fragment is not crystallized. The Fab-like fragment competes effectively for ligands formed by native antibody from which the fragments were produced.