Effect of pH and insulin on fibrillogenesis of islet amyloid polypeptide in vitro

Binding to preformed IAPP fibrils is maximal at acid pH when hIAPP is largely in soluble form. IAPP is secreted together with insulin from the acidic secretory granules (pH 5.5) to the neutral pH of the extracellular space under normal conditions. These changes in pH together with increased accumulation of extracellular hIAPP in diabetes may promote amyloid formation.