Purification, crystallization and initial crystallographic characterization of peanut major allergen Ara h 3

The peanut is a significant food source, but is responsible for many cases of anaphylaxis. The peanut 11S legumin-like seed storage protein Ara h 3 is one of the best characterized allergens. In this study, Ara h 3 was extracted from peanut kernels and purified by sequential anion-exchange, hydrophobic interaction and gel-filtration chromatography to very high purity to facilitate crystallization and structural studies. Well diffracting single crystals were obtained by the vapor-diffusion method. A molecular-replacement structural solution has been obtained and refinement of the structure is currently under way.