Overview of the most commonly used methods in allergen characterization

The characterization of an allergen is a troublesome and difficult process, as it requires both the precise biochemical characterization of a (glyco)protein molecule and the establishment of its susceptibility to IgE antibodies, as they are the main link to histamine release in some hypersensitivity states (type I allergies). As the characterization of an allergen includes molecular weight determination of the allergenic molecule, its structure determination, physicochemical properties, IgE binding properties of the allergen molecule, and its allergenicity, an overall review of which biochemical and immunochemical methods are used in achieving this goal are presented in this paper. The information on the molecular level on the structures of allergens indicates that allergens are considerably heterogeneous protein structures, and that there is no particular aminoacid sequence which is responsible for the allergenicity. Therefore, information gained from detailed structural, functional and immunochemical studies of these intriguing molecules, which nowadays modulate a variety of pathophysiological conditions, would greatly improve our understanding of the underlying disease mechanisms, and the way to handle them.