New routes for PTP1B allosteric inhibition by multitemperature crystallography, fragment screening and covalent tethering
Category
Published on
Type
posted-content
Author
Daniel A Keedy and Zachary B Hill and Justin T Biel and Emily Kang and T. Justin Rettenmaier and Jose Brandao-Neto and Nicholas M Pearce and Frank von Delft and James A. Wells and James S Fraser
Citation
Keedy, D.A. et al., 2017. New routes for PTP1B allosteric inhibition by multitemperature crystallography, fragment screening and covalent tethering. Available at: http://dx.doi.org/10.1101/218966.
Abstract
Allostery is an inherent feature of proteins and provides alternative routes to regulating function. Small-molecule allosteric inhibitors are often desirable; however, it remains challenging to identify surface sites in proteins which can bind small molecules and modulate function. We identified new allosteric sites in protein tyrosine phosphatase 1B (PTP1B) by combining multiple-temperature X-ray crystallography experiments and structure determination from hundreds of individual small-molecule fragment soaks. New modeling approaches reveal "hidden" low-occupancy conformational states for protein and ligands. Our results converge on a new allosteric site that is conformationally coupled to the active-site WPD loop, a hotspot for fragment binding, not conserved in the closest homolog, and distinct from other recently reported allosteric sites in PTP1B. Targeting this site with covalently tethered molecules allosterically inhibits enzyme activity. Overall, this work demonstrates how the ensemble nature of macromolecular structure revealed by multitemperature crystallography can be exploited for developing allosteric modulators.
DOI
Funding
NSF-STC Biology with X-ray Lasers (NSF-1231306)