Fig. 3.

Human neuropsin preproprotein structure. a Shown are: the signal sequence (S) (containing either the type 1-specific amino acid sequence (T1) or type 2-specific amino acid sequence (T2)); the activity-masking peptide (Q) (QGSK in mice and QEDK in human); and the approximate amino acid locations of the characteristic catalytic triad of serine proteases (H, D, and S). b Human neuropsin preprotein amino acid sequence showing the signal sequence (underlined), the activity-masking peptide (yellow) and endoprotease splice sites (red line). Type 2 neuropsin shows a novel endoprotease site (red arrow) in the type 2-specific amino acid sequence (highlighted in grey)