Antigens of aspergillus fumigatus. 1. Purification of a cytoplasmic antigen reactive with sera of patients with aspergillus-related disease.

An antigen has been purified from the mycelial cell sap of Aspergillus fumigatus (strain 507). The same component appears to be present in the extracellular phase (culture filtrate) in a partially degraded form. The cell sap protein has a structure composed of four polypeptides of 45,000 daltons linked through disulphide bonds. The isoelectric point (5.2-5.6) and carbohydrate content (12.5% neutral hexose) indicate that this protein is an acidic glycoprotein. It shows reactions with 75% of sera from patients with aspergilloma and allergic bronchopulmonary aspergillosis and is not reactive with sera from normal individuals of patients with other fungal diseases. It also appears to be a component of other A. fumigatus strains.