Applications of the Microscale Thermophoresis Binding Assay in COVID-19 Research

As the COVID-19 pandemic progresses, new variants of SARS-CoV-2 continue to emerge. This underscores the need to develop optimized tools to study such variants, along with new coronaviruses that may arise in the future. Such tools will also be instrumental in the development of new antiviral drugs. Here, we introduce microscale thermophoresis (MST) as a reliable and versatile tool for coronavirus research, which we demonstrate through three different applications described in this report: (1) binding of the SARS-CoV-2 spike receptor binding domain (RBD) to peptides as a strategy to prevent virus entry, (2) binding of the RBD to the viral receptor ACE2, and (3) binding of the RBD to ACE2 in complex with the amino acid transporter SLC6A20/SIT1 or its allelic variant rs61731475 (p.Ile529Val). Our results demonstrate that MST is a highly precise approach to studying protein-protein and/or protein-ligand interactions in coronavirus research, making it an ideal tool for studying viral variants and developing antiviral agents. Moreover, as shown in our results, a unique advantage of the MST assay over other available binding assays is the ability to measure interactions with membrane proteins in their near-native plasma membrane environment.

Automated summary

As new variants of SARS-CoV-2 continue to emerge during the COVID-19 pandemic, it is crucial to develop optimized tools for studying these variants and potential future coronaviruses. This report introduces microscale thermophoresis (MST) as a reliable and versatile tool for coronavirus research. The study demonstrates three applications of MST, including the binding of SARS-CoV-2 spike receptor binding domain (RBD) to peptides, the binding of RBD to the viral receptor ACE2, and the binding of RBD to ACE2 in complex with the amino acid transporter SLC6A20/SIT1 or its allelic variant rs61731475 (p.Ile529Val). The results highlight MST as a highly precise approach for studying protein interactions and developing antiviral agents in coronavirus research, particularly its advantage in measuring interactions with membrane proteins in their near-native plasma membrane environment.