2. Academic Validation
  3. A Bimane-Based Peptide Staple for Combined Helical Induction and Fluorescent Imaging

A Bimane-Based Peptide Staple for Combined Helical Induction and Fluorescent Imaging

  • Chembiochem. 2020 Dec 1;21(23):3423-3432. doi: 10.1002/cbic.202000485.
Aimee J Horsfall 1 2 3,  Kylie R Dunning 2 3 4,  Kelly L Keeling 1 3,  Denis B Scanlon 1 3,  Kate L Wegener 3 5,  Andrew D Abell 1 2 3
Affiliations

Affiliations

  • 1 The Department of Chemistry, School of Physical Sciences, The University of Adelaide, North Terrace, Adelaide, SA 5005, Australia.
  • 2 The ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), The University of Adelaide, North Terrace, Adelaide, SA 5005, Australia.
  • 3 Institute for Photonics and Advanced Sensing (IPAS), The University of Adelaide, North Terrace, Adelaide, SA 5005, Australia.
  • 4 Robinson Research Institute, Adelaide Medical School, The University of Adelaide, North Terrace, Adelaide, SA 5005, Australia.
  • 5 School of Biological Sciences, The University of Adelaide, North Terrace, Adelaide, SA 5005, Australia.
PMID: 32700428 DOI: 10.1002/cbic.202000485
Abstract

The thiol-selective fluorescent imaging agent, dibromobimane, has been repurposed to crosslink cysteine- and homocysteine-containing Peptides, with the resulting bimane linker acting as both a structural constraint and a fluorescent tag. Macrocyclisation was conducted on nine short Peptides containing two cysteines and/or homocysteines, both on-resin and in buffered aqueous solution, to give macrocycles ranging in size from 16 (i,i+2) to 31 (i,i+7) atoms. The structures were defined by CD, NMR structure calculations by using Xplor-NIH, NMR secondary shift and JHαNH analyses to reveal helical structure in the i,i+4 (1, 2), and i,i+3 (5) constrained Peptides. Cellular-uptake studies were conducted with three of the macrocycles. Subsequent confocal imaging revealed punctate fluorescence within the cytosol indicative of Peptides trapped in endocytic vesicles. These studies demonstrate that dibromobimane is an effective tool for defining secondary structure within short Peptides, whilst simultaneously introducing a fluorescent tag suitable for common cell-based experiments.

Keywords

bimane; fluorescence; helical structures; peptide staple; peptidomimetics.

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