查看文章

Pancreatic amyloid is found in more than 95 % of type II diabetes patients. Pancreatic amyloid is formed by the aggregation of islet amyloid polypeptide (hIAPP or amylin), which is a 37-residue peptide. Because pancreatic amyloid is cytotoxic, it is believed that its formation is directly associated with the development of the disease. We recently showed that hIAPP amyloid formation follows the nucleation-dependent polymerization mechanism and proceeds via a conformational transition of soluble hIAPP into aggregated β-sheets. Here, we report that the penta- and hexapeptide sequences, hIAPP(23–27) (FGAIL) and hIAPP(22–27) (NFGAIL) of hIAPP are sufficient for the formation of β-sheet-containing amyloid fibrils. Although these two peptides differ by only one amino acid residue, they aggregate into completely different fibrillar assemblies. hIAPP(23–27) (FGAIL) fibrils self-assemble laterally into unusually broad …