Flourescent peptide-stabilized silver-nanoclusters: A solid-phase approach for high-throughput ligand discovery

  • Jensen, Knud Jørgen (Supervisor)
  • Vosch, Tom André Jos (Supervisor)
  • Gregersen, Simon (PI (principal investigator))

Projektdetaljer

Beskrivelse

Fluorescent probes are widely used in the fields of imaging, detection, and diagnostics, and in order to achieve methodical progress, the search for new tools is an on-going quest. Within the last few decades, few-atom noble metal nanoclusters (NCs) have gathered increasing attention due to their physical and optoelectronic properties. These include great photostability, low toxicity, small size, and tunable spectral properties. Chemical stability of noble metal NCs is, however, very low, and they only exist transiently without a stabilizing scaffold. This has to date been done in solution using for instance small molecules, DNA oligomers, and proteins. Peptides are an intriguing class of biomolecular ligands, due to the large combinatorial space these provide. Furthermore, as peptides have a propensity to fold up into well-defined and somewhat rigid secondary structures, they may serve as excellent ligands in the synthesis of fluorescent NCs. To date, this class of ligands remains practically unexplored and consequently, not much is known on composition of good peptide ligands for this application. For the first time, we show that employing a solid-phase methodology in this context can increase throughput dramatically with regards to discovery of novel ligands. Our approach employs Fmoc solid-phase peptide synthesis on a PEGA resin which allows for on-resin screening of peptide ligands which, in turn, removes the tedious and labor-intensive work-up of synthesized peptides. The method allows for on-resin formation of peptide-stabilized Ag-NCs in a reversible manner, which makes identification of novel lead compound from combinatorial peptide libraries possible with a few simple steps. This resulted in the discovery of at least one promising candidate (P262) showing brighter emission, spectral homogeneity, and better chemical stability than seen for many Ag-NCs published to date. By physical and optical characterization, we investigate the composition as well as the mechanism for formation of peptide-stabilized fluorescent Ag-NCs, which indicates that the process includes a dynamic folding/reorganization of the peptide to facilitate NC formation. Following an initial chelation involving the thiol-functionality of cysteine side-chains, the coordination of silver into a defined NC is expected to be the driving force of the folding process. This work also illustrates the shortcomings of MALDI-TOF mass spectrometry for the determination of solution-phase composition of organic-silver complexes.
Kort titelFlourescent peptide-stabilized silver-nanoclusters
StatusAfsluttet
Effektiv start/slut dato15/12/201031/07/2014

Finansiering

  • Familien Hede Nielsens Fond: kr 5.000,00
  • William Demant Fonden: kr 5.000,00

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  • Aktiviteter

    • 4 Konferenceoplæg
    • 1 Organisering af eller deltagelse i konference
    • 1 Gæsteophold ved andre institutioner

    23rd American Peptide Symposium

    Simon Gregersen (Andet)
    22 jun. 201327 jun. 2013

    Aktivitet: Foredrag og mundtlige bidragKonferenceoplæg

    University of Kentucky

    Simon Gregersen (Gæsteforsker)
    15 mar. 201320 jun. 2013

    Aktivitet: Gæsteophold ved andre institutioner

    Peptide-Stabilized Fluorescent Silver Nanoclusters

    Simon Gregersen (Oplægsholder)
    11 jun. 2012

    Aktivitet: Foredrag og mundtlige bidragKonferenceoplæg

    Priser

    Young Investigator Poster Award

    Simon Gregersen (Modtager), 27 jun. 2013

    Pris: Konferencepriser

  • Publikation

    • 2 Poster
    • 2 Konferenceabstrakt i tidsskrift
    • 1 Ph.d.-afhandling

    Flourescent peptide-stabilized silver-nanoclusters, a solid-phase approach for high-throughput ligand discovery

    Gregersen, S., 4 feb. 2014, 1 udg. Copenhagen: Copenhagen University. 172 s.

    Publikation: Bog/antologi/afhandling/rapportPh.d.-afhandlingForskning

  • Novel Peptide Ligands for Stabilization of Fluorescent, Silver Nanoclusters: On-resin Screening of a Peptide Library

    Gregersen, S., Jensen, K. J. & Vosch, T. A. J., 13 maj 2013.

    Publikation: Konferencebidrag uden forlag/tidsskriftPosterForskningpeer review

    Novel Peptide Ligands for Stabilization of Fluorescent, Silver Nanoclusters: On-resin Screening of a Peptide Library

    Gregersen, S., Jensen, K. J. & Vosch, T. A. J., 13 maj 2013, I : Journal of Peptide Science. 100, s. 269-270 1 s., YI-P 107.

    Publikation: Bidrag til tidsskriftKonferenceabstrakt i tidsskrift