Generation-dependent effect of PAMAM dendrimers on human insulin fibrillation and thermal stability

Int J Biol Macromol. 2016 Jan:82:54-60. doi: 10.1016/j.ijbiomac.2015.10.029. Epub 2015 Oct 24.

Abstract

We have studied the effect of polyamidoamine (PAMAM) dendrimers of various generations on the thermal stability and fibrillation of human insulin. Thermostability of human insulin used differential scanning calorimetry (DSC), which showed two phase-transitions for insulin at 60 and 82°C. After adding dendrimers at 0.6 μmol/l, the first peaks disappeared and the second peaks were higher. We posited that, in the presence of dendrimers, the dimers in the solution were transformed into hexamers. The effect of dendrimers on insulin fibrillation was monitored by measuring ThT fluorescence, and visualization of insulin fibrils by transmission electron microscopy (TEM) and atomic force microscopy (AFM). The effect of PAMAM dendrimers on insulin fibrillation was strongly dependent on the dendrimers generation and dendrimer:protein ratio.

Keywords: DSC; Insulin; PAMAM dendrimers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid / chemistry*
  • Amyloid / ultrastructure
  • Calorimetry, Differential Scanning
  • Dendrimers / chemistry*
  • Humans
  • Insulin / chemistry*
  • Microscopy, Atomic Force
  • Polymers / chemistry
  • Protein Aggregates*
  • Protein Binding
  • Protein Stability

Substances

  • Amyloid
  • Dendrimers
  • Insulin
  • PAMAM Starburst
  • Polymers
  • Protein Aggregates