Wang Ruijie, Zhang Wenjie, Ma Hailong, Zou Duohong, Zhang Zhiyuan, Wang Shaoyi
Department of Oral Surgery, Shanghai Ninth People's Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China.
Shanghai Key Laboratory of Stomatology, Research Unit of Oral and Maxillofacial Regenerative Medicine, National Center for Stomatology, National Clinical Research Center for Oral Diseases, College of Stomatology, Chinese Academy of Medical Sciences, Shanghai Jiao Tong University, Shanghai, China.
Front Mol Biosci. 2022 Sep 19;9:992473. doi: 10.3389/fmolb.2022.992473. eCollection 2022.
Zoledronic acid (ZOL) inhibits receptor activator of nuclear factor-κB ligand (RANKL) and reduces bone turnover. This plays an important role in the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ). Previous reports have shown that ZOL binds to the enzyme farnesyl pyrophosphate synthase (FPPS) to block its activity. However, the mechanism of action of ZOL and its interaction with RANKL is still unclear. In this study, we confirmed that ZOL significantly suppressed the bone remodeling in ZOL-treated rats, investigated whether ZOL could bind to RANKL and examined the interactions between these molecules at the atomic level. Surface plasmon resonance (SPR) assay was performed to validate that ZOL could directly bind to RANKL in a dose dependent manner, and the equilibrium constant was calculated (K = 2.28 × 10 M). Then, we used molecular docking simulation to predict the binding site and analyze the binding characteristics of ZOL and RANKL. Through molecular dynamics simulation, we confirmed the stable binding between ZOL and RANKL and observed their dynamic interactions over time. Binding free energy calculations and its decomposition were conducted to obtain the binding free energy -70.67 ± 2.62 kJ/mol for the RANKL-ZOL complex. We identified the key residues of RANKL in the binding region, and these included Tyr217(A), Val277(A), Gly278(A), Val277(B), Gly278(B), and Tyr215(C). Taken together, our results demonstrated the direct interaction between ZOL and RANKL, indicating that the pharmacological action of ZOL might be closely related to RANKL. The design of novel small molecules targeting RANKL might reduce the occurrence of BRONJ.
唑来膦酸（ZOL）可抑制核因子κB受体活化因子配体（RANKL）并降低骨转换。这在双膦酸盐相关颌骨坏死（BRONJ）的发生发展中起重要作用。既往报道显示，ZOL与法尼基焦磷酸合酶（FPPS）结合以阻断其活性。然而，ZOL的作用机制及其与RANKL的相互作用仍不清楚。在本研究中，我们证实ZOL显著抑制了ZOL处理大鼠的骨重塑，研究了ZOL是否能与RANKL结合，并在原子水平上研究了这些分子之间的相互作用。进行表面等离子体共振（SPR）分析以验证ZOL能以剂量依赖性方式直接与RANKL结合，并计算了平衡常数（K = 2.28×10⁻⁶ M）。然后，我们使用分子对接模拟来预测结合位点并分析ZOL与RANKL的结合特性。通过分子动力学模拟，我们证实了ZOL与RANKL之间的稳定结合，并观察了它们随时间的动态相互作用。进行结合自由能计算及其分解，得出RANKL-ZOL复合物的结合自由能为-70.67±2.62 kJ/mol。我们确定了RANKL在结合区域的关键残基，这些残基包括Tyr217（A）、Val277（A）、Gly278（A）、Val277（B）、Gly278（B）和Tyr215（C）。综上所述，我们的结果证明了ZOL与RANKL之间的直接相互作用，表明ZOL的药理作用可能与RANKL密切相关。设计靶向RANKL的新型小分子可能会减少BRONJ的发生。
