All you need to know about the house dust mite
For the Curious

The amazing and harmful enzyme from mites, Der p1

The allergen named Der p1 is an active digestive enzyme that can cause cell death in delicate defence cells in the lungs, nose, eyes or on skin. It dose this by 'melting' the glue like substance that binds cells together. The cell's death in turn gives Der p1 access to the body and blood stream.


Der p1 has been likened to the meat tenderisers used in the food industry. The mite makes Der p1 in its gut and then places the enzyme in its dropping in order to breakdown hard-to-digest food for a later dinner. Mites consider their droppings as a future food parcel thanks to Der p1 and other enzymes found in their droppings. A mite can tell when a 'poop' is food because it has an exquisite sense of smell that can detect nourishment.

Hardcore information. Der p1 is a glycoprotein with sequence homology and thiol protease function similar to the enzymes papain, actinidin, bromelain and cathepsins B and H.

1. Papain is a cysteine protease enzyme present in papaya (Carica papaya) and mountain papaya (Vasconcellea cundinamarcensis). Its job is to break down tough meat fibres and has been used for this purpose for thousands of years in its native South America.

2. Actinidin is a type of cysteine protease enzyme found in fruits including kiwi fruit, pineapple, mango, and papaya.

3. Bromelain, derived from the pineapple plant, is one of a group of proteolytic enzymes (enzymes capable of digesting protein).

4. Cathepsins B and H (to be further described)


References

Allergens and Allergen Immunotherapy; Fourth Edition, 2008, Chapter 10, Mite Allergens, Enrique Fernandez-Caldas, Leonardo Puerta, Luis Caraballo, Richard F Lockey, Publisher Taylor & Francis. 'Clin. Allergy Immunol. 2008; 21: 161-182

'Detection of House Dust Mite allergen in amniotic fluid and umbilical-cord blood'; Holloway J A et al, The Lancet, 2000, Issue 9245, 1900-1902.