Effects of common mutations in the SARS-CoV-2 Spike RBD and its ligand, the human ACE2 receptor on binding affinity and kinetics.
Effects of common mutations in the SARS-CoV-2 Spike RBD and its ligand, the human ACE2 receptor on binding affinity and kinetics.
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DOI：
10.7554/elife.70658
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发表时间：
2021-08-26
期刊：
影响因子：
7.7
通讯作者：
van der Merwe PA
中科院分区：
文献类型：
--
作者：
Barton MI;MacGowan SA;Kutuzov MA;Dushek O;Barton GJ;van der Merwe PA
SARS-CoV-2病毒刺突蛋白受体结合域（RBD）与ACE 2细胞表面蛋白之间的相互作用是病毒感染细胞所必需的。RBD中的突变存在于全球独立出现的SARS-CoV-2变异中。例如，B.1.1.7谱系在其刺突RBD中具有增强与ACE 2结合的突变（N501 Y）。在人类中也存在RBD结合位点突变的ACE 2等位基因。在这里，我们对五种常见的RBD突变（K417 N，K417 T，N501 Y，E484 K和S477 N）和两种常见的ACE 2突变（S19 P和K26 R）对RBD/ACE 2相互作用的影响进行了详细的亲和力和动力学分析。我们分析了在新的SARS-CoV-2 α（B.1.1.7），β（B.1.351）和γ（P1）变体中发现的单个RBD突变和组合的影响。这些突变中的大多数增加了RBD/ACE 2相互作用的亲和力。例外的是突变K417 N/T，其降低了亲和力。结合其他研究，我们的结果表明，N501 Y和S477 N突变主要通过增强结合来增强传播，K417 N/T突变促进免疫逃逸，E484 K突变增强结合和免疫逃逸。随着COVID-19大流行的发展，出现了比原始形式更具传染性的SARS-CoV-2病毒的新变体。被称为Alpha，Beta和Gamma的变体在病毒表面的一种蛋白质中发生了突变，这种蛋白质对于附着细胞并感染它们至关重要。这种被称为Spike的蛋白质通过与人类细胞表面的蛋白质ACE 2结合来发挥作用。刺突上的突变在其与ACE 2结合的区域上发现。这两种蛋白质之间的相互作用似乎对SARS-CoV-2的行为很重要，但Spike中单个突变的影响尚不清楚。此外，有些人有不同的ACE 2变异体，与Spike相互作用的区域发生突变，但目前尚不清楚这是否会影响这些人感染COVID-19的风险。为了回答这些问题，巴顿等人测量了Spike和ACE 2突变对两种蛋白质之间相互作用强度的精确影响。实验表明，在α、β和γ SARS-CoV-2变体中的五种常见刺突突变中，有三种增强了与ACE 2的结合。这两个削弱结合的突变只与其他加强结合的突变一起发现。这意味着这三种SARS-CoV-2变异体中的刺突蛋白与ACE 2的结合比原始形式更强。实验还表明，ACE 2的两种常见变体也增加了与Spike结合的强度。有趣的是，其中一种ACE 2变异体逆转了特定SARS-CoV-2突变的影响，表明携带者对具有这种突变的SARS-CoV-2变异体具有抗性。确定刺突突变对ACE 2结合的精确影响有助于理解为什么SARS-CoV-2的新变体传播得更快。这可能有助于在新变种广泛传播之前识别出相关变种，并为卫生当局的应对措施提供信息。两种常见的ACE 2变体与Spike结合更强的发现表明，具有这些突变的人可能更容易感染SARS-CoV-2。
The interaction between the SARS-CoV-2 virus Spike protein receptor binding domain (RBD) and the ACE2 cell surface protein is required for viral infection of cells. Mutations in the RBD are present in SARS-CoV-2 variants of concern that have emerged independently worldwide. For example, the B.1.1.7 lineage has a mutation (N501Y) in its Spike RBD that enhances binding to ACE2. There are also ACE2 alleles in humans with mutations in the RBD binding site. Here we perform a detailed affinity and kinetics analysis of the effect of five common RBD mutations (K417N, K417T, N501Y, E484K, and S477N) and two common ACE2 mutations (S19P and K26R) on the RBD/ACE2 interaction. We analysed the effects of individual RBD mutations and combinations found in new SARS-CoV-2 Alpha (B.1.1.7), Beta (B.1.351), and Gamma (P1) variants. Most of these mutations increased the affinity of the RBD/ACE2 interaction. The exceptions were mutations K417N/T, which decreased the affinity. Taken together with other studies, our results suggest that the N501Y and S477N mutations enhance transmission primarily by enhancing binding, the K417N/T mutations facilitate immune escape, and the E484K mutation enhances binding and immune escape. As the COVID-19 pandemic has progressed, new variants of the virus SARS-CoV-2 have emerged that are more infectious than the original form. The variants known as Alpha, Beta and Gamma have mutations in a protein on the virus’s surface that is vital for attaching to cells and infecting them. This protein, called Spike, carries out its role by binding to ACE2, a protein on the surface of human cells. Mutations on Spike are found on the region where it binds to ACE2. The interaction between these two proteins appears to be important to the behaviour of SARS-CoV-2, but the impact of individual mutations in Spike is unknown. In addition, some people have different variants of ACE2 with mutations in the region that interacts with Spike, but it is not known whether this affects these people’s risk of contracting COVID-19. To answer these questions, Barton et al. measured the precise effect of mutations in Spike and ACE2 on the strength of the interaction between the two proteins. The experiments showed that three of the five common Spike mutations in the Alpha, Beta and Gamma SARS-CoV-2 variants strengthened binding to ACE2. The two mutations that weakened binding were only found together with other mutations that strengthened binding. This meant that the Spike proteins in all three of these SARS-CoV-2 variants bind to ACE2 more strongly than the original form. The experiments also showed that two common variants of ACE2 also increased the strength of binding to Spike. Interestingly, one of these ACE2 variants reversed the effect of a specific SARS-CoV-2 mutation, suggesting that carriers would be resistant to SARS-CoV-2 variants with this mutation. Identifying the precise effects of Spike mutations on ACE2 binding helps understand why new variants of SARS-CoV-2 spread more rapidly. This could help to identify concerning new variants before they spread widely and inform the response by health authorities. The finding that two common ACE2 variants bind more strongly to Spike suggests that people with these mutations could be more susceptible to SARS-CoV-2.