Chirality-assisted ring-like aggregation of aβ(1-40) at liquid-solid interfaces: a stereoselective two-step assembly process

Angew Chem Int Ed Engl. 2015 Feb 9;54(7):2245-50. doi: 10.1002/anie.201410768. Epub 2014 Dec 22.

Abstract

Molecular chirality is introduced at liquid-solid interfaces. A ring-like aggregation of amyloid Aβ(1-40) on N-isobutyryl-L-cysteine (L-NIBC)-modified gold substrate occurs at low Aβ(1-40) concentration, while D-NIBC modification only results in rod-like aggregation. Utilizing atomic force microscope controlled tip-enhanced Raman scattering, we directly observe the secondary structure information for Aβ(1-40) assembly in situ at the nanoscale. D- or L-NIBC on the surface can guide parallel or nonparallel alignment of β-hairpins through a two-step process based on electrostatic-interaction-enhanced adsorption and subsequent stereoselective recognition. Possible electrostatic interaction sites (R5 and K16) and a chiral recognition site (H14) of Aβ(1-40) are proposed, which may provide insight into the understanding of this effect.

Keywords: amyloids; chirality; stereoselectivity; surface assembly; surface interactions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amyloid beta-Peptides / chemistry*
  • Amyloid beta-Peptides / ultrastructure
  • Cysteine / analogs & derivatives
  • Cysteine / chemistry
  • Gold / chemistry
  • Humans
  • Microscopy, Atomic Force
  • Peptide Fragments / chemistry*
  • Peptide Fragments / ultrastructure
  • Protein Aggregates*
  • Protein Structure, Secondary
  • Static Electricity
  • Stereoisomerism
  • Surface Properties

Substances

  • Amyloid beta-Peptides
  • Peptide Fragments
  • Protein Aggregates
  • amyloid beta-protein (1-40)
  • N-isobutyrylcysteine
  • Gold
  • Cysteine