Chiral Fibers Formation Upon Assembly of Tetraphenylalanine Peptide Conjugated to a PNA Dimer

Chemistry. 2022 Jul 1;28(37):e202200693. doi: 10.1002/chem.202200693. Epub 2022 May 23.

Abstract

Self-assembly of biomolecules such as peptides, nucleic acids or their analogues affords supramolecular objects, exhibiting structures and physical properties dependent on the amino-acid or nucleobase composition. Conjugation of the peptide diphenylalanine (FF) to peptide nucleic acids triggers formation of self-assembled structures, mainly stabilized by interactions between FF. In this work we report formation of homogeneous chiral fibers upon self-assembly of the hybrid composed of the tetraphenylalanine peptide (4F) conjugated to the PNA dimer adenine-thymine (at). In this case nucleobases seem to play a key role in determining the morphology and chirality of the fibers. When the PNA "at" is replaced by guanine-cytosine dimer "gc", disordered structures are observed. Spectroscopic characterization of the self-assembled hybrids, along with AFM and SEM studies is reported. Finally, a structural model consistent with the experimental evidence has also been obtained, showing how the building blocks of 4Fat arrange to give helical fibers.

Keywords: assembly; fiber; helix; peptide; peptide nucleic acid.

MeSH terms

  • Nanostructures* / chemistry
  • Peptide Nucleic Acids* / chemistry
  • Peptides / chemistry
  • Phenylalanine / chemistry
  • Polymers
  • Thymine

Substances

  • Peptide Nucleic Acids
  • Peptides
  • Polymers
  • diphenylalanine
  • Phenylalanine
  • Thymine