A structure-guided computational approach was used to identifyallosteric druggable sites in PTHR and to predict compounds that would bind to this site, and Pitt researchers discovered four small-molecule compounds that act as negative allosteric modulators of PTHR signaling. Parathyroid hormone (PTH) type 1 receptor (PTHR) is an indispensable G protein-coupled receptor (GPCR) of class B that functions to regulate blood levels of vitamin D, calcium, and phosphate ions in the body, as well as bone turnover. A structure-guided computational approach was used to identify allosteric druggable sites in PTHR and to predict compounds that would bind to this site, and Pitt researchers discovered four small-molecule compounds that act as negative allosteric modulators of PTHR signaling.