title: Predicting Allosteric Effects from Orthosteric Binding in Hsp90-Ligand Interactions: Implications for Fragment-Based Drug Design.
abstract: A key question in mapping dynamics of protein-ligand interactions is to distinguish changes at binding sites from those associated with long range conformational changes upon binding at distal sites. This assumes a greater challenge when considering the interactions of low affinity ligands (dissociation constants, KD, in the μM range or lower). Amide hydrogen deuterium Exchange mass spectrometry (HDXMS) is a robust method that can provide both structural insights and dynamics information on both high affinity and transient protein-ligand interactions. In this study, an application of HDXMS for probing the dynamics of low affinity ligands to proteins is described using the N-terminal ATPase domain of Hsp90. Comparison of Hsp90 dynamics between high affinity natural inhibitors (KD ~ nM) and fragment compounds reveal that HDXMS is highly sensitive in mapping the interactions of both high and low affinity ligands. HDXMS reports on changes that reflect both orthosteric effects and allosteric changes accompanying binding. Orthosteric sites can be identified by overlaying HDXMS onto structural information of protein-ligand complexes. Regions distal to orthosteric sites indicate long range conformational changes with implications for allostery. HDXMS, thus finds powerful utility as a high throughput method for compound library screening to identify binding sites and describe allostery with important implications for fragment-based ligand discovery (FBLD).
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Arun
authors.initials: A
authors.lastname: Chandramohan
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Srinath
authors.identifier: 0000-0002-4175-5886
authors.initials: S
authors.lastname: Krishnamurthy
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore.
authors.forename: Andreas
authors.initials: A
authors.lastname: Larsson
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore.
authors.forename: Paer
authors.initials: P
authors.lastname: Nordlund
authors.affiliation: School of Biological Sciences, Nanyang Technological University, Singapore.
authors.forename: Anna
authors.initials: A
authors.lastname: Jansson
authors.affiliation: Department of Biological Sciences, National University of Singapore, Singapore.
authors.forename: Ganesh S
authors.initials: GS
authors.lastname: Anand
mesh_terms: D000495:Allosteric Site; D001665:Binding Sites; D041961:Deuterium Exchange Measurement / Q000379:methods*; D015195:Drug Design; D004789:Enzyme Activation; D018841:HSP90 Heat-Shock Proteins / Q000737:chemistry* / Q000648:ultrastructure*; D008024:Ligands; D013058:Mass Spectrometry / Q000379:methods*; D062105:Molecular Docking Simulation / Q000379:methods; D011485:Protein Binding; D011487:Protein Conformation; D025941:Protein Interaction Mapping / Q000379:methods*; D013379:Substrate Specificity
chemical_list: D018841:HSP90 Heat-Shock Proteins; D008024:Ligands