The importance of being Aib. Aggregation and self-assembly studies on conformationally constrained oligopeptides

J Pept Sci. 2017 Feb;23(2):104-116. doi: 10.1002/psc.2956. Epub 2017 Jan 5.

Abstract

The role of the conformationally constrained α-aminoisobutyric acid (Aib) residue in the aggregation and self-assembly properties of oligopeptides is discussed, critically reviewing our recent work in the field. In this connection, three significant case studies are presented: (i) aggregation propensity of Aib homo-oligopeptides of different length; (ii) perturbation of the conformational and aggregation properties of Ala-based pentapeptides by a single Aib versus Ala substitution; and (iii) build up of self-assembled monolayers formed by Aib homo-hexapeptide building blocks. The peptides investigated were all functionalized by a fluorescent probe, that is, a naphthyl group in the first case-study and a pyrenyl group in the other two, with the aim at applying optical spectroscopy techniques and evaluating the relevance of aromatic interactions in the aggregation process. Microscopy techniques at nanometric resolution and results of molecular dynamics simulations are also presented to analyze how the conformational properties of the peptide building blocks would affect the morphology of the peptide aggregates from the nanoscale to the mesoscale. Copyright © 2017 European Peptide Society and John Wiley & Sons, Ltd.

Keywords: conformationally constrained α-amino acid; peptide aggregation; peptide fibers; peptide self-assembled monolayers; α-aminoisobutyric acid.

Publication types

  • Review

MeSH terms

  • Amino Acid Sequence
  • Aminoisobutyric Acids / chemistry*
  • Fluorescent Dyes / chemistry
  • Hydrogen Bonding
  • Microscopy, Atomic Force
  • Molecular Dynamics Simulation
  • Molecular Probes / chemistry
  • Oligopeptides / chemistry*
  • Protein Aggregates*
  • Protein Structure, Secondary
  • Solutions
  • Spectrometry, Fluorescence

Substances

  • Aminoisobutyric Acids
  • Fluorescent Dyes
  • Molecular Probes
  • Oligopeptides
  • Protein Aggregates
  • Solutions
  • 2-aminoisobutyric acid