Modular Ligation of Thioamide Functional Peptides onto Solid Cellulose Substrates

Authors

  • Thomas Tischer,

    1. Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstr. 18, 76128 Karlsruhe, Germany
    Search for more papers by this author
  • Anja S. Goldmann,

    1. Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstr. 18, 76128 Karlsruhe, Germany
    Search for more papers by this author
  • Katharina Linkert,

    1. Laboratory for Organic Synthesis of Functional Systems, Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany
    Search for more papers by this author
  • Vanessa Trouillet,

    1. Institute for Applied Materials (IAM-WPT), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany
    Search for more papers by this author
  • Hans G. Börner,

    Corresponding author
    1. Laboratory for Organic Synthesis of Functional Systems, Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany
    • Laboratory for Organic Synthesis of Functional Systems, Department of Chemistry, Humboldt-Universität zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin, Germany.
    Search for more papers by this author
  • Christopher Barner-Kowollik

    Corresponding author
    1. Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstr. 18, 76128 Karlsruhe, Germany
    • Preparative Macromolecular Chemistry, Institut für Technische Chemie und Polymerchemie, Karlsruhe Institute of Technology (KIT), Engesserstr. 18, 76128 Karlsruhe, Germany
    Search for more papers by this author

Abstract

Hetero Diels-Alder (HDA) cycloaddition – as an effective modular conjugation approach – is employed to graft thioamide endfunctional oligopeptides onto solid cyclopentadienyl (Cp) functional cellulose substrates generating cellulose-peptide hybrid materials. The highly reactive Cp moieties serve as diene functionality in the consecutive HDA reaction on the biosubstrate surface. Oligopeptides (i.e., the model peptide Gly-Gly-Arg-Phe-Pro-Trp-Trp-Gly and the antimicrobial peptide tritrpticin) are functionalized at their N-termini employing strongly electron deficient thiocarbonyl thio compounds resulting in biomacromolecules bearing a thioamide endgroup. The dienophile- functional peptides readily undergo HDA reactions at ambient temperature and under mild conditions in solution with synthetic polymers as well as on solid (bio)substrates. An in-depth investigation is provided of the influence of the temperature, the Lewis acid catalysis and the side group exchange of thioamide functional oligopeptides reacting with Cp terminated poly(methyl methacrylate) (Mn = 2100 g·mol−1, PDI = 1.1) in homogenous solution as well as Cp functionalized cellulose in a heterogeneous system. To assess the success of the grafting reaction, the soluble samples were subjected to characterization methods such as size exclusion chromatography (SEC) and SEC-electrospray ionization mass spectrometry (SEC-ESI-MS). The heterogeneous “grafting-to” reactions were monitored using high resolution attenuated total reflection (ATR) Fourier transform infrared microscopy (HR-FTIRM) imaging, X-ray photoelectron spectroscopy (XPS) and elemental analysis. Evaluation via elemental analysis leads to quantitative peptide cellulose surface loading capacities.

Ancillary