Binding affinity properties of dendritic glycosides based on a beta-cyclodextrin core toward guest molecules and concanavalin A

J Org Chem. 2001 Nov 16;66(23):7786-95. doi: 10.1021/jo015875q.

Abstract

The inclusion behavior and concanavalin A binding properties of hepta-antennated and newly synthesized tetradeca-antennated C-6-branched mannopyranosyl and glucopyrannosyl cyclomaltoheptaose (beta-cyclodextrin) derivatives have been evaluated by isothermal titration microcalorimetry and enzyme-linked lectin assay (ELLA), respectively. The synthesis of three first-order dendrimers based on a beta-cyclodextrin core containing 14 1-thio-beta-D-glucose, 1-thio-beta-mannose, and 1-thio-beta-rhamnose residues was performed following a convergent approach and involving (1) preparation of a thiolated bis-branched glycoside building block and (2) attachment of the building block onto heptakis(6-deoxy-6-iodo)-beta-cyclodextrin. Calorimetric titrations performed at 25 degrees C in buffered aqueous solution (pH 7.4) gave the affinity constants and the thermodynamic parameters for the inclusion complex formation of these beta-cyclodextrin derivatives with guests sodium 8-anilino-1-naphthalensulfonate (ANS) and 2-naphthalenesulfonate. The host capability of the persubstituted beta-cyclodextrins decreased with respect to the native beta-CD when sodium 2-naphthalenesulfonate was used as a guest and improved when ANS was used as a guest molecule. Heptavalent mannoclusters based on beta-CD cores enhance the lectin binding affinity due to the cluster effect; however, the increase of the valency from 7 to 14 ligands did not contribute to the improvement of the concanavalin A binding affinity. In addition, the synthesized hyperbranched mannoCDs lost completely the capability as a host molecules.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calorimetry
  • Carbohydrate Sequence
  • Concanavalin A / metabolism*
  • Cyclodextrins / chemistry*
  • Cyclodextrins / metabolism*
  • Enzyme-Linked Immunosorbent Assay
  • Glycosides / chemistry*
  • Glycosides / metabolism*
  • Lectins / metabolism*
  • Molecular Sequence Data
  • Protein Binding
  • Receptors, Concanavalin A / metabolism
  • beta-Cyclodextrins*

Substances

  • Cyclodextrins
  • Glycosides
  • Lectins
  • Receptors, Concanavalin A
  • beta-Cyclodextrins
  • Concanavalin A
  • betadex