The Utility of Native MS for Understanding the Mechanism of Action of Repurposed Therapeutics in COVID-19: Heparin as a Disruptor of the SARS-CoV-2 Interaction with Its Host Cell Receptor
The Utility of Native MS for Understanding the Mechanism of Action of Repurposed Therapeutics in COVID-19: Heparin as a Disruptor of the SARS-CoV-2 Interaction with Its Host Cell Receptor
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DOI：
10.1021/acs.analchem.0c02449
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发表时间：
2020-07
影响因子：
7.4
通讯作者：
Yang Yang-Yang;Yi Du;I. Kaltashov
中科院分区：
文献类型：
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作者：
Yang Yang-Yang;Yi Du;I. Kaltashov
新型冠状病毒(SARS-CoV-2)的出现和迅速扩散导致了一场全球大流行，截至2020年5月底，全球报告的病例超过600万例，死亡近40万人。对治愈方法的急于寻找促使人们重新评估现有的一系列疗法及其在治疗新冠肺炎中的潜在作用，并将重点放在能够支持此类努力的分析工具上。天然质谱学(MS)长期以来一直是支持药物/治疗靶点相互作用机制研究的首选工具，但在涉及高度结构异质性系统的情况下，其应用仍然有限。SARS-CoV-2刺突蛋白(S蛋白)是病毒进入宿主细胞的关键元件，它和它在宿主细胞表面的停靠部位ACE2都是广泛糖基化的，使它们成为天然MS的挑战靶点。然而，用气相离子操纵技术(有限电荷减少)补充天然MS允许获得关于ACE2和S蛋白的受体结合域形成的非共价复合体的有意义的信息。将这一技术与分子模拟结合使用，也可以研究肝素在破坏ACE2/RBD结合的稳定中的作用，为了解其干扰病毒与宿主细胞受体对接的分子机制提供关键信息。短的(五糖)和相对长的(二十糖)肝素低聚物与RBD形成1：1的络合物，表明存在一个单一的结合位点。这种结合改变了蛋白质的构象(最大化RBD表面正电荷的连续斑块)，导致其与ACE2结合的能力显著下降。肝素的不稳定作用在较长链的情况下更为明显，这是由于低等电点的ACE2与不位于RBD表面的肝素片段之间的静电斥力。除了提供有关肝素减弱血管紧张素转换酶/RBD结合的重要机制信息外，该研究还展示了天然MS与气相离子化学相结合的尚未开发的潜力，以促进治疗新冠肺炎的现有药物的合理再利用。
The emergence and rapid proliferation of the novel coronavirus (SARS-CoV-2) resulted in a global pandemic, with over 6,000,000 cases and nearly 400,000 deaths reported worldwide by the end of May 2020. A rush to find a cure prompted re-evaluation of a range of existing therapeutics vis-à-vis their potential role in treating COVID-19, placing a premium on analytical tools capable of supporting such efforts. Native mass spectrometry (MS) has long been a tool of choice in supporting the mechanistic studies of drug/therapeutic target interactions, but its applications remain limited in the cases that involve systems with a high level of structural heterogeneity. Both SARS-CoV-2 spike protein (S-protein), a critical element of the viral entry to the host cell, and ACE2, its docking site on the host cell surface, are extensively glycosylated, making them challenging targets for native MS. However, supplementing native MS with a gas-phase ion manipulation technique (limited charge reduction) allows meaningful information to be obtained on the noncovalent complexes formed by ACE2 and the receptor-binding domain (RBD) of the S-protein. Using this technique in combination with molecular modeling also allows the role of heparin in destabilizing the ACE2/RBD association to be studied, providing critical information for understanding the molecular mechanism of its interference with the virus docking to the host cell receptor. Both short (pentasaccharide) and relatively long (eicosasaccharide) heparin oligomers form 1:1 complexes with RBD, indicating the presence of a single binding site. This association alters the protein conformation (to maximize the contiguous patch of the positive charge on the RBD surface), resulting in a notable decrease in its ability to associate with ACE2. The destabilizing effect of heparin is more pronounced in the case of the longer chains due to the electrostatic repulsion between the low-pI ACE2 and the heparin segments not accommodated on the RBD surface. In addition to providing important mechanistic information on attenuation of the ACE2/RBD association by heparin, the study demonstrates the yet untapped potential of native MS coupled to gas-phase ion chemistry as a means of facilitating rational repurposing of the existing medicines for treating COVID-19.