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bioRxiv · 10.1101/2022.06.20.496903

Probing the biophysical constraints of SARS-CoV-2 spike N-terminal domain using deep mutational scanning

Ouyang, W. O.·Tan, T. J. C.·Lei, R.·Song, G.·Kieffer, C.·Andrabi, R.·Matreyek, K. A.·Wu, N. C.
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Abstract

Increasing the expression level of the SARS-CoV-2 spike (S) protein has been critical for COVID-19 vaccine development. While previous efforts largely focused on engineering the receptor-binding domain (RBD) and the S2 subunit, the N-terminal domain (NTD) has been long overlooked due to the limited understanding of its biophysical constraints. In this study, the effects of thousands of NTD single mutations on S protein expression were quantified by deep mutational scanning. Our results revealed that in terms of S protein expression, the mutational tolerability of NTD residues was inversely correlated with their proximity to the RBD and S2. We also identified NTD mutations at the interdomain interface that increased S protein expression without altering its antigenicity. Overall, this study not only advances the understanding of the biophysical constraints of the NTD, but also provides invaluable insights into S-based immunogen design.

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Ouyang, W. O., Tan, T. J. C., Lei, R., Song, G., Kieffer, C., Andrabi, R., Matreyek, K. A., Wu, N. C.. 2022-06-21. Probing the biophysical constraints of SARS-CoV-2 spike N-terminal domain using deep mutational scanning. https://doi.org/10.1101/2022.06.20.496903

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