Studies of Highly-Ordered Heterodiantennary Mannose/Glucose-Functionalized Polymers and Concanavalin A Protein Interactions Using Isothermal Titration Calorimetry

Biomacromolecules. 2015 Dec 14;16(12):4013-4021. doi: 10.1021/acs.biomac.5b01380. Epub 2015 Dec 1.

Abstract

Preparations of the highly ordered monoantennary, homofunctional diantennary, and heterofunctional diantennary neoglycopolymers of α-d-mannose and β-d-glucose residues were achieved via ring-opening metathesis polymerization. Isothermal titration calorimetry measurements of these synthetic neoglycopolymers with Concanavalin A (Con A), revealed that heterofunctional diantennary architectures bearing both α-mannose and nonbinding β-glucose units, poly(Man-Glc), binds to Con A (Ka = 16.1 × 10(6) M(-1)) comparably to homofunctional diantennary neoglycopolymer (Ka = 30 × 10(6) M(-1)) bearing only α-mannose unit, poly(Man-Man). In addition, poly(Man-Glc) neoglycopolymer shows a nearly 5-fold increasing in binding affinity compared to monoantennary neoglycopolymer, poly(Man). Although the exact mechanism for the high binding affinity of poly(Man-Glc) to Con A is unclear, we hypothesize that the α-mannose bound to Con A might facilitate interaction of β-glucose with the extended binding site of Con A due to the close proximity of β-glucose to α-mannose residues in the designed polymerizable scaffold.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Binding Sites
  • Calorimetry / methods
  • Carbohydrate Conformation
  • Concanavalin A / chemistry*
  • Glucose / chemistry*
  • Kinetics
  • Mannose / chemistry*
  • Polymerization

Substances

  • Concanavalin A
  • Glucose
  • Mannose