Napsin A Aspartic Peptidase (NAPSA)

Napsin-A is a protein encoded by the NAPSA gene.The activation peptides of aspartic proteinases plays role as inhibitors of the active site. These peptide segments, or pro-parts, are deemed important for correct folding, targeting, and control of the activation of aspartic proteinase zymogens.

The pronapsin A gene is expressed predominantly in lung and kidney. Its translation product is predicted to be a fully functional, glycosylated aspartic proteinase precursor containing an RGD motif and an additional 18 residues at its C-terminus. Expressed predominantly in adult lung (type II pneumocytes) and kidney and in fetal lung. Low levels in adult spleen and very low levels in peripheral blood leukocytes.