Timeline Event - year 1988 Early DNA analysis identifies the major mite allergen (Der p1) as an active enzyme.   The major house dust mite allergen, is identified as an active enzyme with properties similar to papain.  Papain is commonly used in food manufacturing as a meat tenderizer. Reference ‘Sequence Analysis of cDNA coding for a major house dust mite allergen Der p1’, Chua K.Y. et al,  J.Exp. Med., Vol. 167 Jan 1988, pages 175 to 182