title: Domain-specific interactions between MLN8237 and human serum albumin estimated by STD and WaterLOGSY NMR, ITC, spectroscopic, and docking techniques.
abstract: Alisertib (MLN8237) is an orally administered inhibitor of Aurora A kinase. This small-molecule inhibitor is under clinical or pre-clinical phase for the treatment of advanced malignancies. The present study provides a detailed characterization of the interaction of MLN8237 with a drug transport protein called human serum albumin (HSA). STD and WaterLOGSY nuclear magnetic resonance (NMR)-binding studies were conducted first to confirm the binding of MLN8237 to HSA. In the ligand orientation assay, the binding sites of MLN8237 were validated through two site-specific spy molecules (warfarin sodium and ibuprofen, which are two known site-selective probes) by using STD and WaterLOGSY NMR competition techniques. These competition experiments demonstrate that both spy molecules do not compete with MLN8237 for the specific binding site. The AutoDock-based blind docking study recognizes the hydrophobic subdomain IB of the protein as the probable binding site for MLN8237. Thermodynamic investigations by isothermal titration calorimetry (ITC) reveal that the non-covalent interaction between MLN8237 and HSA (binding constant was approximately 105M-1) is driven mainly by favorable entropy and unfavorable enthalpy. In addition, synchronous fluorescence, circular dichroism (CD), and 3D fluorescence spectroscopy suggest that MLN8237 may induce conformational changes in HSA.
authors.affiliation: College of Chemical Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
authors.forename: Hongqin
authors.initials: H
authors.lastname: Yang
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei 230026, People's Republic of China.
authors.forename: Jiuyang
authors.initials: J
authors.lastname: Liu
authors.affiliation: College of Chemical Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
authors.forename: Yanmei
authors.initials: Y
authors.lastname: Huang
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei 230026, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Gao
authors.affiliation: College of Chemical Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
authors.forename: Bin
authors.initials: B
authors.lastname: Tang
authors.affiliation: College of Chemical Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
authors.forename: Shanshan
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Chemical Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
authors.forename: Jiawei
authors.initials: J
authors.lastname: He
authors.affiliation: College of Chemical Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
authors.forename: Hui
authors.initials: H
authors.lastname: Li
mesh_terms: D001381:Azepines / Q000737:chemistry* / Q000378:metabolism*; D001665:Binding Sites; D002151:Calorimetry; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D062105:Molecular Docking Simulation; D011485:Protein Binding; D000072417:Protein Domains; D011743:Pyrimidines / Q000737:chemistry* / Q000378:metabolism*; D000075462:Serum Albumin, Human / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D001381:Azepines; C550258:MLN 8237; D011743:Pyrimidines; D000075462:Serum Albumin, Human