Biomedical Engineering Reference
In-Depth Information
Figure 1
Inhibition of NE-mediated degradation and cleavage reactions by
AAT. Neutrophil elastase is released from neutrophils and causes the activation
of IL-8 by respiratory epithelium, as well as the cleavage of IgG receptor on neu-
trophils and the PSR on macrophages. These events are inhibited by AAT. In
addition, AAT prevents defensin-induced IL-8 production by
respiratory
epithelium.
III.
SECRETORY LEUKOPROTEASE INHIBITOR
Secretory leukoprotease inhibitor was initially identified as serine protease
inhibitor present in a number of bodily secretions including nasal, bron-
chial, salivary, tear, and seminal secretions (35-38). The SLPI gene is
2.65 kb in length and is composed of four exons and three introns (39).
The mature protein is 11.7 kDa in size, consisting of 107 amino acids
and comprising two domains (40). Each domain is homologous to the
whey acid protein (WAP) motif, a protein sequence composed of four
disulfide bridges and ~50 amino acids in length (41). Secretory leukopro-
tease inhibitor and elafin (described later in this chapter) are the best
