AFFINITY PURIFICATION OF THE MAJOR BOVINE ALLERGEN BY A NOVEL MONOCLONAL-ANTIBODY

A monoclonal antibody was developed to the 20 kd major allergen of cow by immunizing mice with crude dander extract. The monoclonal antibody did not exhibit cross-reactivity to cat, dog, and horse dander extrac ts when studied by ELISA inhibition. The antibody was used in affinity chromatography for the purification of the 20 kd allergen from cow da nder extract. Purity of the allergen was estimated to be 88%, and alle rgenic reactivity was verified by IgE immunoblotting and skin prick te sts. After further purification with size-exclusion chromatography, th e allergen was almost 100% pure. The isoelectric point of the double-p urified allergen was determined to be 4.1. The amino acid composition was characterized by the predominance of acidic amino acids.