Islet Amyloid Polypeptide: Structure, Function, and Pathophysiology

Figure 2

Processing of human PreProIAPP to produce mature IAPP. (a) The primary sequence of the 89-residue human PreProIAPP. The 22-residue signal sequence is shown in italics; the N- and C-terminal proIAPP flanking regions are underlined. (b) Primary sequence of the 67-residue proform of human IAPP. Pro-hIAPP is cleaved by the prohormone convertases PC(1/3) and PC2 at two conserved dibasic sites, indicated by arrows. The amidated C-terminus is produced after further processing by CPE/PAM. (c) The sequence of the mature 37-residue human IAPP. The biologically active peptide has an amidated C-terminus and a disulfide bridge between Cys-2 and Cys-7.