Allergens of mammalian origin: Characterization of allergen extracted from cat pelts

Abstract

An aqueous extract prepared from lyophylized, defatted cat pelts elicited intense wheal-and-flare responses in the skin of patients exhibiting asthma or rhinitis on exposure to cats. On electrophoresis of the extract in agarose, protein bands with the mobility of albumin, α 2-, β-, and γ 1-protein were observed. Allergenic activity was localized in two distinct regions with albumin and α 2-mobility, respectively. Allergenic activity remained bound to DE52-cellulose columns equilibrated with phosphatebuffered (0.01M, pH 7.4) saline (0.05M), but could be eluted by increasing the salt concentration to 0.25M. Following gel filtration on Sephadex G-100, allergen was recovered in fractions containing proteins with a molecular weight range of 30,000 to 60,000 daltons. A purified fraction of cat pelt extract obtained by sequential fractionation on DE52-cellulose and Sephadex G-100 columns was subjected to polyacrylamide disc gel electrophoresis; 5 protein bands were observed. Allergenic activity was recovered in fractions containing two of these bands. Five of twelve subjects with strong skin reactivity to cat pelt extract also reacted strongly to cat serum; the major allergen in cat serum was found to have the electrophoretic mobility of α 2-protein.