Hydrophobic spacers enhance the helicity and lectin binding of synthetic, pH-responsive glycopolypeptides

Biomacromolecules. 2014 Dec 8;15(12):4528-33. doi: 10.1021/bm501325n. Epub 2014 Nov 21.

Abstract

The influence of different hydrophobic spacers on the structural and lectin binding properties of well-defined glycopolypeptides decorated with galactose moieties was investigated. All glycopolypeptides were prepared from a poly(α,l-glutamic acid) (PGA) precursor via a polymer-analogous aqueous amide coupling reaction. Thereby, two alkyl spacers of different length (C6 and C11) as well as an aromatic spacer were introduced between the backbone and the galactose moieties, as confirmed by (1)H NMR spectroscopy. The secondary structure was investigated as a function of the sugar density and the pH by circular dichroism (CD) spectroscopy. It was found that the helicity in acidic medium and thus the typical coil-to-helix transition is strongly enhanced by the hydrophobic spacers. Preliminary lectin binding tests via turbidimetric assay revealed that the spacers also significantly enhance the interaction of the glycopolypeptides with the lectin RCA120.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Circular Dichroism
  • Galactose / chemistry
  • Glycopeptides / chemistry*
  • Hydrogen-Ion Concentration
  • Hydrophobic and Hydrophilic Interactions*
  • Lectins / chemistry*
  • Magnetic Resonance Spectroscopy
  • Polyglutamic Acid / chemistry
  • Polymers / chemistry
  • Protein Structure, Secondary
  • Water / chemistry

Substances

  • Glycopeptides
  • Lectins
  • Polymers
  • Water
  • Polyglutamic Acid
  • Galactose