Serological Relationships between Collagenase and the A 2 -Isoagglutinogen-like Substance of Animal Parasites. ∗

Summary

The A₂ isoagglutinogen-like substance (A₂IS) from animal parasites has been prepared in a purified form from crude extracts of the cuticle of Ascaris lumbricoides var suum. Preliminary chemical studies indicated that this substance is a glycoprotein. The A₂IS is related to collagenase or a collagenase complex, as shown by cross hemagglutination reactions between anticollagenase sera prepared in rabbits, and the A₂IS substances adsorbed onto tannic acid treated Group O human erythrocytes. Also A₂IS reacts with anticollagenase sera in agar diffusion slides with formation of one band of precipitate. The two substances are also immunologically related as shown by the fact that they inhibit the a ₂ isoagglutinins in human serum of Groups O and B when comparable amount of each substance is used per ml of serum. A₂IS and collagenase also cause anaphylactoid symptoms and death when injected intravenously into dogs. It is suggested that collagenase or substances in the collagenase complex are present in infectious organisms which may be associated with hypersensitivity.