Description
This enzyme, derived from the house dust mite, is a major component of the allergic immune response. The substrate specificity of this enzyme is not altogether clear. It cleaves the low-affinity IgE receptor CD23 at Glu298┼Ser299 and Ser155┼Ser156. It also cleaves the pulmonary structural proteins occludin and claudin at Leu┼Leu, Asp┼Leu and at Gly┼Thr bonds. It can also cleave the α subunit of the interleukin-2 (IL-2) receptor (CD25). Using a positional scanning combinatorial library, it was found that the major substrate-specificity determinant is for Ala in the P2 position. 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.Belongs in peptidase family C1A