Fluorine Pseudocontact Shifts Used for Characterizing the Protein–Ligand Interaction Mode in the Limit of NMR Intermediate Exchange. Issue 42 (19th September 2017)

• Record Type: Journal Article
• Authors: Gao, Jia; Liang, E; Ma, Rongsheng; Li, Fudong; Liu, Yixiang; Liu, Jiuyang; Jiang, Ling; Li, Conggang; Dai, Haiming; Wu, Jihui; Su, Xuncheng; He, Wei; Ruan, Ke
• Is Part Of: Angewandte Chemie international edition. Volume 56:Issue 42(2017)
• Page Start: 12982
• Page End: 12986
• Publication Date: 2017-09-19
• Subjects: chemical exchange saturation transfer -- bromodomains -- inhibitors -- NMR spectroscopy -- pseudocontact shifts; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.201707114
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: The characterization of protein–ligand interaction modes becomes recalcitrant in the NMR intermediate exchange regime as the interface resonances are broadened beyond detection. Here, we determined the 19 F low‐populated bound‐state pseudocontact shifts (PCSs) of mono‐ and di‐fluorinated inhibitors of the BRM bromodomain using a highly skewed protein/ligand ratio. The bound‐state 19 F PCSs were retrieved from 19 F chemical exchange saturation transfer (CEST) in the presence of the lanthanide‐labeled protein, which was termed the 19 F PCS‐CEST approach. These PCSs enriched in spatial information enabled the identification of best‐fitting poses, which agree well with the crystal structure of a more soluble analog in complex with the BRM bromodomain. This approach fills the gap of the NMR structural characterization of lead‐like inhibitors with moderate affinities to target proteins, which are essential for structure‐guided hit‐to‐lead evolution. Abstract : The severe line broadening in the intermediate exchange limits the applicability of NMR spectroscopy for interrogating the interaction modes of lead‐like inhibitors with moderate affinities to target proteins. A 19 F chemical exchange saturation transfer approach is used to retrieve the low‐populated bound‐state 19 F pseudocontact shifts, which enable the identification of the best binding pose of the BRM bromodomain inhibitor.