Report

A Trivalent System from Vancomycin·d-Ala-d-Ala with Higher Affinity Than Avidin·Biotin

See allHide authors and affiliations

Science  01 May 1998:
Vol. 280, Issue 5364, pp. 708-711
DOI: 10.1126/science.280.5364.708

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Tris(vancomycin carboxamide) binds a trivalent ligand derived fromd-Ala-d-Ala with very high affinity: dissociation constant (K d) ≈ 4 × 10–17 ± 1 × 10–17 M. High-affinity trivalent binding and monovalent binding are fundamentally different. In trivalent (and more generally, polyvalent) binding, dissociation occurs in stages, and its rate can be accelerated by monovalent ligand at sufficiently high concentrations. In monovalent binding, dissociation is determined solely by the rate constant for dissociation and cannot be accelerated by added monomer. Calorimetric measurements for the trivalent system indicate an approximately additive gain in enthalpy relative to the corresponding monomers. This system is one of the most stable organic receptor-ligand pairs involving small molecules that is known. It illustrates the practicality of designing very high-affinity systems based on polyvalency.

  • * To whom correspondence should be addressed. E-mail: gwhitesides{at}gmwgroup.harvard.edu

View Full Text