title: Towards a structural understanding of allosteric drugs at the human calcium-sensing receptor.
abstract: Drugs that allosterically target the human calcium-sensing receptor (CaSR) have substantial therapeutic potential, but are currently limited. Given the absence of high-resolution structures of the CaSR, we combined mutagenesis with a novel analytical approach and molecular modeling to develop an "enriched" picture of structure-function requirements for interaction between Ca(2+)o and allosteric modulators within the CaSR's 7 transmembrane (7TM) domain. An extended cavity that accommodates multiple binding sites for structurally diverse ligands was identified. Phenylalkylamines bind to a site that overlaps with a putative Ca(2+)o-binding site and extends towards an extracellular vestibule. In contrast, the structurally and pharmacologically distinct AC-265347 binds deeper within the 7TM domains. Furthermore, distinct amino acid networks were found to mediate cooperativity by different modulators. These findings may facilitate the rational design of allosteric modulators with distinct and potentially pathway-biased pharmacological effects.
authors.affiliation: Drug Discovery Biology, Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
authors.forename: Katie
authors.initials: K
authors.lastname: Leach
authors.affiliation: Drug Discovery Biology, Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Gregory
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92037, USA.
authors.forename: Irina
authors.initials: I
authors.lastname: Kufareva
authors.affiliation: Drug Discovery Biology, Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
authors.forename: Elham
authors.initials: E
authors.lastname: Khajehali
authors.affiliation: Drug Discovery Biology, Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
authors.forename: Anna E
authors.initials: AE
authors.lastname: Cook
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92037, USA.
authors.forename: Ruben
authors.initials: R
authors.lastname: Abagyan
authors.affiliation: School of Molecular Bioscience, Charles Perkins Centre, University of Sydney, NSW 2006, Australia.
authors.forename: Arthur D
authors.initials: AD
authors.lastname: Conigrave
authors.affiliation: Drug Discovery Biology, Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
authors.forename: Patrick M
authors.initials: PM
authors.lastname: Sexton
authors.affiliation: Drug Discovery Biology, Department of Pharmacology, Monash Institute of Pharmaceutical Sciences, Monash University, 381 Royal Parade, Parkville, VIC 3052, Australia.
authors.forename: Arthur
authors.initials: A
authors.lastname: Christopoulos
mesh_terms: D000494:Allosteric Regulation; D000588:Amines / Q000737:chemistry; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000235:genetics; D001665:Binding Sites; D002118:Calcium / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D009154:Mutation / Q000235:genetics; D004364:Pharmaceutical Preparations / Q000737:chemistry* / Q000378:metabolism*; D044169:Receptors, Calcium-Sensing / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D013329:Structure-Activity Relationship
chemical_list: D000588:Amines; D000596:Amino Acids; D004364:Pharmaceutical Preparations; D044169:Receptors, Calcium-Sensing; D002118:Calcium