Isolation and partial characterization of a major peanut allergen.
We isolated and partially characterized a major peanut allergen (Peanut-I) using the radioallergosorbent test (RAST) to monitor the allergenicity of various fractions. Raw peanuts were pulverized, defatted, and extracted; the resulting crude extract (CPE) was fractionated by diethylaminoethyl (DEAE) cellulose anion-exchange chromatography using a linear salt gradient. Peak allergenic fractions were further purified by a second DEAE cellulose chromatography step, followed by a preparative polyacrylamide gel electrophoresis (PAGE) step. The final product, Peanut-I, contained 11% nitrogen and 8.7% carbohydrate and was homogeneous by both analytical PAGE and immunoelectrophoresis against rabbit anti-CPE. Peanut-I was heterogeneous by thin-layer electrofocusing and by PAGE in 1% sodium dodecyl sulfate. Biologic activity of Peanut-I was demonstrated by positive skin tests and leukocyte histamine release assays in patients with peanut allergy. By RAST inhibition assay Peanut-I did not account for all of the allergenic activity of CPE.
D000485:Allergens / Q000302:isolation & purification*; D000818:Animals; D010367:Arachis / Q000276:immunology*; D005591:Chemical Fractionation; D004591:Electrophoresis, Polyacrylamide Gel; D006601:Hexoses; D006636:Histamine Release; D006801:Humans; D009584:Nitrogen; D010936:Plant Extracts / Q000276:immunology; D011817:Rabbits; D011852:Radioallergosorbent Test; D012882:Skin Tests
D000485:Allergens; D006601:Hexoses; D010936:Plant Extracts; D009584:Nitrogen