Thermal effect on the degradation of hIAPP20-29 fibrils

Abstract

Uncontrolled misfolding of proteins resulting in the formation of amyloid deposits is associated with over 40 types of diseases, for instance, type-2 diabetes. The human Islet amyloid polypeptide (hIAPP) amyloid formation is thought to be the cause of type-2 diabetes occurrence. A possible strategy to the current challenge of reducing the toxicity of its aggregates to pancreatic β-cell is the discovery of an efficient way to degrading amyloid deposits. In this work, hIAPP_20-29, a core fibrillating fragment of hIAPP, was selected as model system to explore the thermal effect at different temperature on the degradation of hIAPP_20-29 mature fibrils. Insights on the degradation mechanism are obtained by analyzing the morphologies, the mechanical properties, the interactions between the peptides, and the secondary structure of amyloid aggregates. In addition, thermal degradation displayed a possible way to breaking the interaction of peptides and further disassembling the amyloid fibrils. These findings may initiate a new avenue to degrade the amyloid peptide aggregates and enrich and update the current selection of nanostructure modulations.

Keywords: Atomic force microscopy; Degradation of amyloid aggregates; Nanomechanical mapping; Scanning probe microscopy; Thermal effect.