Energetics of Displacing Water Molecules from Protein Binding Sites: Consequences for Ligand Optimization

Julien Michel, Julian Tirado-Rives and William L. Jorgensen*
Department of Chemistry, Yale University, New Haven, Connecticut 06520
J. Am. Chem. Soc., 2009, 131 (42), pp 15403–15411
DOI: 10.1021/ja906058w
Publication Date (Web): September 24, 2009
Copyright © 2009 American Chemical Society

Abstract

Abstract Image

A strategy in drug design is to consider enhancing the affinity of lead molecules with structural modifications that displace water molecules from a protein binding site. Because success of the approach is uncertain, clarification of the associated energetics was sought in cases where similar structural modifications yield qualitatively different outcomes. Specifically, free-energy perturbation calculations were carried out in the context of Monte Carlo statistical mechanics simulations to investigate ligand series that feature displacement of ordered water molecules in the binding sites of scytalone dehydratase, p38-αMAP kinase, and EGFR kinase. The change in affinity for a ligand modification is found to correlate with the ease of displacement of the ordered water molecule. However, as in the EGFR example, the binding affinity may diminish if the free-energy increase due to the removal of the bound water molecule is not more than compensated by the additional interactions of the water-displacing moiety. For accurate computation of the effects of ligand modifications, a complete thermodynamic analysis is shown to be needed. It requires identification of the location of water molecules in the protein−ligand interface and evaluation of the free-energy changes associated with their removal and with the introduction of the ligand modification. Direct modification of the ligand in free-energy calculations is likely to trap the ordered molecule and provide misleading guidance for lead optimization.

Citing Articles

View all 14 citing articles

Citation data is made available by participants in CrossRef's Cited-by Linking service. For a more comprehensive list of citations to this article, users are encouraged to perform a search in SciFinder.

This article has been cited by 14 ACS Journal articles (5 most recent appear below).

Tools

SciFinder Links

SciFinder subscribers:  Click to sign in | Not a SciFinder subscriber? Learn more at www.cas.org

Explore by:


Accession Codes

History

  • Published In Issue October 28, 2009
  • Article ASAPSeptember 24, 2009
  • Received: July 20, 2009

Recommend & Share

  • Share on ACS NetworkACS Network
  • Add to FacebookFacebook
  • Tweet ThisTweet This
  • Add to CiteULikeCiteULike
  • Add to NewsvineNewsvine
  • Digg ThisDigg This
  • Add to DeliciousDelicious

Related Content

Other ACS content by these authors: