EC 3.4.22.65

Reaction: Broad endopeptidase specificity

Other name(s): allergen Der f 1; allergen Der p 1; antigen Der p 1; antigen Eur m 1; antigen Pso o 1; major mite fecal allergen Der p 1; Der p 1; Der f 1; Eur m 1; endopeptidase 1 (mite)

Comments: This enzyme, derived from the house dust mite, is a major component of the allergic immune response [2]. The substrate specificity of this enzyme is not altogether clear. It cleaves the low-affinity IgE receptor CD23 at Glu²⁹⁸Ser²⁹⁹ and Ser¹⁵⁵Ser¹⁵⁶ [1]. It also cleaves the pulmonary structural proteins occludin and claudin at LeuLeu, AspLeu and at GlyThr bonds [1,2]. It can also cleave the α subunit of the interleukin-2 (IL-2) receptor (CD25) [4]. Using a positional scanning combinatorial library, it was found that the major substrate-specificity determinant is for Ala in the P2 position [3]. The enzyme shows only a slight preference for basic amino acids in the P1 and P3 positions and a preference for aliphatic amino acids such as Ile, Pro, Val, Leu and norleucine in the P4 position [3]. Belongs in peptidase family C1A.

Links to other databases: BRENDA, EXPASY, KEGG, MEROPS, Metacyc, PDB, CAS registry number:

References:

1. Meighan, P. and Pirzad, R. Mite endopeptidase 1. In: Barrett, A.J., Rawlings, N.D. and Woessner, J.F. (Eds), Handbook of Proteolytic Enzymes, 2nd edn, Elsevier, London, 2004, pp. 1187-1189.

2. Kalsheker, N.A., Deam, S., Chambers, L., Sreedharan, S., Brocklehurst, K. and Lomas, D.A. The house dust mite allergen Der p1 catalytically inactivates α1-antitrypsin by specific reactive centre loop cleavage: a mechanism that promotes airway inflammation and asthma. Biochem. Biophys. Res. Commun. 221 (1996) 59-61. [PMID: 8660343]

3. Harris, J., Mason, D.E., Li, J., Burdick, K.W., Backes, B.J., Chen, T., Shipway, A., Van Heeke, G., Gough, L., Ghaemmaghami, A., Shakib, F., Debaene, F. and Winssinger, N. Activity profile of dust mite allergen extract using substrate libraries and functional proteomic microarrays. Chem. Biol. 11 (2004) 1361-1372. [PMID: 15489163]

4. Schulz, O., Sewell, H.F. and Shakib, F. Proteolytic cleavage of CD25, the α subunit of the human T cell interleukin 2 receptor, by Der p 1, a major mite allergen with cysteine protease activity. J. Exp. Med. 187 (1998) 271-275. [PMID: 9432986]

5. Schulz, O., Sewell, H.F. and Shakib, F. A sensitive fluorescent assay for measuring the cysteine protease activity of Der p 1, a major allergen from the dust mite Dermatophagoides pteronyssinus. Mol. Pathol. 51 (1998) 222-224. [PMID: 9893750]

6. Takai, T., Kato, T., Sakata, Y., Yasueda, H., Izuhara, K., Okumura, K. and Ogawa, H. Recombinant Der p 1 and Der f 1 exhibit cysteine protease activity but no serine protease activity. Biochem. Biophys. Res. Commun. 328 (2005) 944-952. [PMID: 15707969]