Synthesis and evaluation of a photoactive probe with a multivalent carbohydrate for capturing carbohydrate-lectin interactions

Bioconjug Chem. 2013 Nov 20;24(11):1895-906. doi: 10.1021/bc400306g. Epub 2013 Nov 6.

Abstract

Lectins are ubiquitous carbohydrate-binding proteins of nonimmune origin that are characterized by their specific recognition of defined monosaccharide or oligosaccharide structures. However, the use of carbohydrates to study lectin has been restricted by the weak binding affinity and noncovalent character of the interaction between carbohydrates and lectin. In this report, we designed and synthesized a multifunctional photoaffinity reagent composed of a trialkyne chain, a masked latent amine group, and a photoreactive 3-trifluoromethyl-3-phenyl-diazirine group in high overall yield. Two well-defined chemistries, Huisgen-Sharpless click chemistry and amide bond coupling, were the key steps for installing the multivalent character and tag in our designed photoaffinity probe. The photolabeling results demonstrated that the designed probe selectively labeled the target lectin, RCA120 ( Ricinus communis Agglutinin), in an E. coli lysate and an asialoglycoprotein receptor (ASGP-R) on intact HepG2 cell membranes. Moreover, the probe also enabled the detection of weak protein-protein interactions between RCA120 and ovalbumin (OVA).

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkynes / chemistry
  • Azirines / chemical synthesis*
  • Azirines / chemistry
  • Carbohydrates / chemistry*
  • Cell Membrane / chemistry
  • Hep G2 Cells
  • Humans
  • Models, Molecular
  • Molecular Structure
  • Ovalbumin / chemistry
  • Photochemical Processes
  • Photosensitizing Agents / chemical synthesis*
  • Photosensitizing Agents / chemistry
  • Plant Lectins / chemistry*

Substances

  • 3-trifluoromethyl-3-phenyldiazirine
  • Alkynes
  • Azirines
  • Carbohydrates
  • Photosensitizing Agents
  • Plant Lectins
  • Ricinus communis agglutinin-1
  • Ovalbumin