The isolation and characterization of a novel collagenolytic serine protease allergen (Der p 9) from the dust mite Dermatophagoides pteronyssinus

J Allergy Clin Immunol. 1996 Oct;98(4):739-47. doi: 10.1016/s0091-6749(96)70121-5.


Background: Dust mites have been shown to contain a serine protease distinct from the previously reported trypsin and chymotrypsin. The latter enzymes have been shown to be allergens, but the allergenic importance of the former is unknown.

Objective: This study was performed to isolate and characterize the novel mite serine protease and determine its allergenicity.

Methods: The mite serine protease was isolated from feces-enriched extracts of Dermatophagoides pteronyssinus by ion-exchange chromatography and affinity chromatography, and its physicochemical properties were determined. The allergenicity of the protease was assessed by using the RAST.

Results: The protease was enzymatically similar to chymotrypsin and cathepsin G-like enzymes from a variety of sources and was shown to cleave collagen. It had a molecular mass of 23,780 d. N-terminal sequence analysis (18 residues) indicated homology with the mite tryptic allergen, Der p 3, and the chymotryptic allergen, Der p 6. RAST analyses showed that the frequencies of reactivity to the novel allergen and to Der p 1, Der p 2, Der p 3, and Der p 6 were 92%, 97%, 100%, 97%, and 65%, respectively (n = 35). RAST inhibition studies showed some cross-reactivity between the protease and Der p 3 but not Der p 6.

Conclusions: A novel mite serine protease was isolated from D. pteronyssinus and found to be a major allergen. This allergen has been tentatively designated Der p 9.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Allergens / isolation & purification*
  • Amino Acid Sequence
  • Animals
  • Antigens, Dermatophagoides
  • Chromatography, Affinity
  • Collagen / metabolism
  • Collagenases / immunology*
  • Collagenases / isolation & purification
  • Cross Reactions
  • Dust
  • Glycoproteins / immunology
  • Glycoproteins / isolation & purification*
  • Humans
  • Hypersensitivity / immunology
  • Mites / enzymology*
  • Mites / immunology*
  • Molecular Sequence Data
  • Molecular Weight
  • Radioallergosorbent Test
  • Sequence Alignment
  • Serine Endopeptidases / immunology*


  • Allergens
  • Antigens, Dermatophagoides
  • Dust
  • Glycoproteins
  • Collagen
  • Serine Endopeptidases
  • Collagenases