Simplified Methods for Purification of Peanut Allergenic Proteins: Ara h 1, Ara h 2, and Ara h 3

Simplified methods to purify major peanut allergens (Ara h 1, Ara h 2, and Ara h 3) were investigated to facilitate current laborious and time-consuming conventional purification methods, the combination of ammonium sulfate fractionation (ASF) and successive column chromatographic separations. Crude peanut proteins obtained from defatted peanut were subjected to ASF at higher concentrations of ammonium sulfate than those in conventional methods and then dialyzed against water. Purified Ara h 1, Ara h 2, and Ara h 3 were obtained by ultrafiltration(s) of the dialyzed supernatant in ASF (80 - 90%), the dialyzed precipitate in ASF (40 - 50%), and the dialyzed precipitate in ASF (0 - 40%), respectively. The purities of Ara h 1, Ara h 2, and Ara h 3 were 91.3%, 86.4%, and 93.9%, respectively. The simplified methods enable the purification of the three major peanut allergens in a relatively short time without the use of chromatographic separation techniques.