College of Chemical Engineering, Sichuan University, Chengdu 610065, People's Republic of China.
School of Life Sciences, University of Science and Technology of China, Hefei 230026, People's Republic of China.
Sci Rep. 2017 Mar 30;7:45514. doi: 10.1038/srep45514.
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 10 M) 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.
alisertib（MLN8237）是一种口服的 Aurora A 激酶抑制剂。这种小分子抑制剂正处于临床或临床前阶段，用于治疗晚期恶性肿瘤。本研究详细描述了 MLN8237 与人血清白蛋白（HSA）这种药物转运蛋白的相互作用。首先进行 STD 和 WaterLOGSY 核磁共振（NMR）结合研究，以确认 MLN8237 与 HSA 的结合。在配体定位试验中，通过两种特异性间谍分子（华法林钠和布洛芬，这两种是已知的选择性探针），使用 STD 和 WaterLOGSY NMR 竞争技术，验证了 MLN8237 的结合位点。这些竞争实验表明，这两种间谍分子都不与 MLN8237 竞争特定结合位点。基于 AutoDock 的盲目对接研究识别出蛋白的疏水亚基 IB 是 MLN8237 的可能结合位点。等温滴定量热法（ITC）的热力学研究表明，MLN8237 与 HSA 之间的非共价相互作用（结合常数约为 10 M）主要由有利的熵和不利的焓驱动。此外，同步荧光、圆二色性（CD）和 3D 荧光光谱表明，MLN8237 可能会引起 HSA 的构象变化。
