The relationship between ligand-binding thermodynamics and protein-ligand interaction forces measured by atomic force microscopy.

Journal Article

The interaction forces between biotin and a set of streptavidin site-directed mutants with altered biotin-binding equilibrium and activation thermodynamics have been measured by atomic force microscopy. The AFM technique readily discriminates differences in interaction force between the site-directed (Trp to Phe or Ala) mutants. The interaction force is poorly correlated with both the equilibrium free energy of biotin binding and the activation free energy barrier to dissociation of the biotin-streptavidin complex. The interaction force is generally well correlated with the equilibrium biotin-binding enthalpy as well as the enthalpic activation barrier, but in the one mutant where these two parameters are altered in opposite directions, the interaction force is clearly correlated with the activation enthalpy of dissociation. These results suggest that the AFM force measurements directly probe the enthalpic activation barrier to ligand dissociation.

Full Text

Duke Authors

Cited Authors

  • Chilkoti, A; Boland, T; Ratner, BD; Stayton, PS

Published Date

  • November 1995

Published In

Volume / Issue

  • 69 / 5

Start / End Page

  • 2125 - 2130

PubMed ID

  • 8580356

International Standard Serial Number (ISSN)

  • 0006-3495

Digital Object Identifier (DOI)

  • 10.1016/S0006-3495(95)80083-4

Language

  • eng

Conference Location

  • United States