The antigens of pigeon breeder's disease. II. Isolation and characterization of antigen PDE1.

Antigen PDE1 was purified from pigeon dropping extracts by chromatography on DEAE-cellulose and Bio-Gel A-1.5. It was characterized as a glycoprotein, containing 88% protein and 12% carbohydrate, with a molecular weight of approximately 200,000. PDE1 appears to be derived from pigeon intestinal IgA, showing the typical immunoglobulin structure of heavy and light chains. This antigen represents about 24% of the dry weight of the unfractionated pigeon dropping extract.