PT  - JOURNAL ARTICLE
AU  - Daniel A. Keedy
AU  - Zachary B. Hill
AU  - Justin T. Biel
AU  - Emily Kang
AU  - T. Justin Rettenmaier
AU  - Jose Brandao-Neto
AU  - Nicholas M. Pearce
AU  - Frank von Delft
AU  - James A. Wells
AU  - James S. Fraser
TI  - New routes for PTP1B allosteric inhibition by multitemperature crystallography, fragment screening and covalent tethering
AID  - 10.1101/218966
DP  - 2017 Jan 01
TA  - bioRxiv
PG  - 218966
4099  - http://biorxiv.org/content/early/2017/11/13/218966.short
4100  - http://biorxiv.org/content/early/2017/11/13/218966.full
AB  - 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.