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Title: qFit-ligand Reveals Widespread Conformational Heterogeneity of Drug-Like Molecules in X-Ray Electron Density Maps

Journal Article · · Journal of Medicinal Chemistry
 [1]; ORCiD logo [2];  [3];  [2];  [4];  [5];  [2];  [1];  [1];  [2]; ORCiD logo [6]
  1. Schrodinger, New York, NY (United States)
  2. UCSF, San Francisco, CA (United States)
  3. Stanford Univ., Stanford, CA (United States). SLAC National Accelerator Lab
  4. Stanford Univ., Stanford, CA (United States)
  5. Univ. Paris-Saclay, Palaiseau (France)
  6. UCSF, San Francisco, CA (United States); Stanford Univ., Stanford, CA (United States). SLAC National Accelerator Lab

Here, proteins and ligands sample a conformational ensemble that governs molecular recognition, activity, and dissociation. In structure-based drug design, access to this conformational ensemble is critical to understand the balance between entropy and enthalpy in lead optimization. However, ligand conformational heterogeneity is currently severely underreported in crystal structures in the Protein Data Bank, owing in part to a lack of automated and unbiased procedures to model an ensemble of protein–ligand states into X-ray data. Here, we designed a computational method, qFit-ligand, to automatically resolve conformationally averaged ligand heterogeneity in crystal structures, and applied it to a large set of protein receptor–ligand complexes. In an analysis of the cancer related BRD4 domain, we found that up to 29% of protein crystal structures bound with drug-like molecules present evidence of unmodeled, averaged, relatively isoenergetic conformations in ligand–receptor interactions. In many retrospective cases, these alternate conformations were adventitiously exploited to guide compound design, resulting in improved potency or selectivity. Combining qFit-ligand with high-throughput screening or multitemperature crystallography could therefore augment the structure-based drug design toolbox.

Research Organization:
SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States)
Sponsoring Organization:
USDOE
Grant/Contract Number:
AC02-76SF00515
OSTI ID:
1493576
Journal Information:
Journal of Medicinal Chemistry, Journal Name: Journal of Medicinal Chemistry Journal Issue: 24 Vol. 61; ISSN 0022-2623
Publisher:
American Chemical Society (ACS)Copyright Statement
Country of Publication:
United States
Language:
English

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Cited By (6)

Performance evaluation of molecular docking and free energy calculations protocols using the D3R Grand Challenge 4 dataset journal November 2019
Performance evaluation of molecular docking and free energy calculations protocols using the D3R Grand Challenge 4 dataset journal November 2019
An investigation of structural stability in protein-ligand complexes reveals the balance between order and disorder journal September 2019
Mix-and-inject XFEL crystallography reveals gated conformational dynamics during enzyme catalysis journal December 2019
Shining light on cysteine modification: connecting protein conformational dynamics to catalysis and regulation journal June 2019
Journey to the center of the protein: allostery from multitemperature multiconformer X-ray crystallography journal January 2019

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