Rabbit Anti-House Dust Mite Der p 1, Der f 1 monoclonal antibody for ELISA. Der p 1 is a 25 kDa glycoprotein composed of a 222-amino acid sequence encoded by the gene DERP1. Der p 1 is synthesized as an inactive 80-amino acid protein precursor known as protein Der p 1, which is then cleaved and activated by mature Der p 1. Der f 1 is a thiol protease that hydrolyzes proteins, with a preference for Phe or basic residues. Der f 1 is a C1 peptidase family member. Der f 1 has extensive endopeptidase specificity. Der f 1 causes an allergic reaction in humans. Common symptoms of mite allergy are bronchial asthma, allergic rhinitis and conjunctivitis.