{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"The activation peptides of aspartic proteinases play a 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 addition 18 residues at its C-terminus."}]}]}