Helical Sulfono-γ-AApeptides with Aggregation-Induced Emission and Circularly Polarized Luminescence

J Am Chem Soc. 2019 Aug 14;141(32):12697-12706. doi: 10.1021/jacs.9b05329. Epub 2019 Aug 5.

Abstract

Aggregation-induced emission (AIE) was intensively studied because of packing of small molecules and polymers; however, mid-molecular-weight (1000-3000) molecular scaffold containing a precise number of AIE luminogens is rare. Herein, we report the investigation of three tetraphenylethylene (TPE)-modified sulfono-γ-AApeptides in which multiple TPE moieties are conjugated to the chiral right-handed helical peptidomimetic backbone as functional side chains. The crystal structure of the TPE-α/sulfono-γ-AA peptide 1 demonstrates that because of the rigid helical scaffold of the TPE-α/sulfono-γ-AA peptides, the intramolecular rotations of the TPE with short linker are restricted, therefore leading to the boosted fluorescent emission in solution. Peptides 2 and 3 exhibit aggregation-induced emission enhancement (AIEE), possibly because of the combination of both AIE and rotation restriction. Moreover, because of their preoriented assembly induced by the right-handed helical scaffold, these emissive chiral luminogens show effective circularly polarized luminescence signals with high dissymmetry factor glum. Finally, the amphiphilic nature of TPE-α/sulfono-γ-AA peptides could enable them to penetrate the bacterial membranes and exhibit strong fluorescence. Their antimicrobial activity and labeling-free character could further augment their potential applications in both materials and biomedical sciences.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • Bacillus subtilis / drug effects
  • Escherichia coli / drug effects
  • Fluorescence
  • Fluorescent Dyes / chemistry
  • Fluorescent Dyes / pharmacology*
  • Methicillin-Resistant Staphylococcus aureus / drug effects
  • Microbial Sensitivity Tests
  • Peptides / chemistry
  • Peptides / pharmacology*
  • Protein Conformation, alpha-Helical
  • Protein Multimerization
  • Protein Structure, Quaternary
  • Stilbenes / chemistry
  • Stilbenes / pharmacology*
  • Sulfones / chemistry
  • Sulfones / pharmacology*

Substances

  • Anti-Bacterial Agents
  • Fluorescent Dyes
  • Peptides
  • Stilbenes
  • Sulfones