Adnan Mohd, DasGupta Debarati, Anwar Saleha, Shamsi Anas, Siddiqui Arif Jamal, Snoussi Mejdi, Bardakci Fevzi, Patel Mitesh, Hassan Md Imtaiyaz
Department of Biology, College of Science, University of Ha'il, Ha'il, Saudi Arabia.
College of Pharmacy, University of Michigan, Ann Arbor, MI, United States.
Front Pharmacol. 2023 Sep 19;14:1276179. doi: 10.3389/fphar.2023.1276179. eCollection 2023.
Hyperphosphorylation of tau is an important event in Alzheimer's disease (AD) pathogenesis, leading to the generation of "neurofibrillary tangles," a histopathological hallmark associated with the onset of AD and related tauopathies. Microtubule-affinity regulating kinase 4 (MARK4) is an evolutionarily conserved Ser-Thr (S/T) kinase that phosphorylates tau and microtubule-associated proteins, thus playing a critical role in AD pathology. The uncontrolled neuronal migration is attributed to overexpressed MARK4, leading to disruption in microtubule dynamics. Inhibiting MARK4 is an attractive strategy in AD therapeutics. Molecular docking was performed to see the interactions between MARK4 and galantamine (GLT). Furthermore, 250 ns molecular dynamic studies were performed to investigate the stability and conformational dynamics of the MARK4-GLT complex. We performed fluorescence binding and isothermal titration calorimetry studies to measure the binding affinity between GLT and MARK4. Finally, an enzyme inhibition assay was performed to measure the MARK4 activity in the presence and absence of GLT. We showed that GLT, an acetylcholinesterase inhibitor, binds to the active site cavity of MARK4 with an appreciable binding affinity. Molecular dynamic simulation for 250 ns demonstrated the stability and conformational dynamics of the MARK4-GLT complex. Fluorescence binding and isothermal titration calorimetry studies suggested a strong binding affinity. We further show that GLT inhibits the kinase activity of MARK4 significantly (IC = 5.87 µM). These results suggest that GLT is a potential inhibitor of MARK4 and could be a promising therapeutic target for AD. GLT's inhibition of MARK4 provides newer insights into the mechanism of GLT's action, which is already used to improve cognition in AD patients.
tau蛋白的过度磷酸化是阿尔茨海默病（AD）发病机制中的一个重要事件，会导致“神经原纤维缠结”的产生，这是一种与AD及相关tau蛋白病发病相关的组织病理学特征。微管亲和调节激酶4（MARK4）是一种进化上保守的丝氨酸 - 苏氨酸（S/T）激酶，它使tau蛋白和微管相关蛋白磷酸化，因此在AD病理学中起关键作用。不受控制的神经元迁移归因于MARK4的过度表达，导致微管动力学紊乱。抑制MARK4是AD治疗中的一个有吸引力的策略。进行了分子对接以观察MARK4与加兰他敏（GLT）之间的相互作用。此外，进行了250纳秒的分子动力学研究，以研究MARK4 - GLT复合物的稳定性和构象动力学。我们进行了荧光结合和等温滴定量热法研究，以测量GLT与MARK4之间的结合亲和力。最后，进行了酶抑制试验，以测量在有和没有GLT存在的情况下MARK4的活性。我们表明，乙酰胆碱酯酶抑制剂GLT以可观的结合亲和力与MARK4的活性位点腔结合。250纳秒的分子动力学模拟证明了MARK4 - GLT复合物的稳定性和构象动力学。荧光结合和等温滴定量热法研究表明有很强的结合亲和力。我们进一步表明，GLT显著抑制MARK4的激酶活性（IC = 5.87 μM）。这些结果表明，GLT是MARK4的潜在抑制剂，可能是AD的一个有前景的治疗靶点。GLT对MARK4的抑制为GLT的作用机制提供了新的见解，GLT已被用于改善AD患者的认知。
