Stabilizing the closed SARS-CoV-2 spike trimer

Nature Communications, vol. 12, pp. 244

Abstract

The trimeric spike (S) protein of SARS-CoV-2 is the primary focus of most vaccine design and development efforts. Due to intrinsic instability typical of class I fusion proteins, S tends to prematurely refold to the post-fusion conformation, compromising immunogenic properties and prefusion trimer yields. To support ongoing vaccine development efforts, we report the structure-based design of soluble S trimers with increased yields and stabilities, based on introduction of single point mutations and disulfide-bridges. We identify regions critical for stability: the heptad repeat region 1, the SD1 domain and position 614 in SD2. We combine a minimal selection of mostly interprotomeric mutations to create a stable S-closed variant with a 6.4-fold higher expression than the parental construct while no longer containing a heterologous trimerization domain. The cryo-EM structure reveals a correctly folded, predominantly closed pre-fusion conformation. Highly stable and well producing S protein and the increased understanding of S protein structure will support vaccine development and serological diagnostics.

Authors 9

1. Jarek Juraszek Aachen Janssen Vaccines & Prevention B.V

   Janssen (Netherlands)

   Affiliation as printed

   Janssen Vaccines & Prevention B.V., Archimedesweg 4-6, Leiden, The Netherlands

2. Lucy Rutten Aachen Janssen Vaccines & Prevention B.V

   Janssen (Netherlands)

   Affiliation as printed

   Janssen Vaccines & Prevention B.V., Archimedesweg 4-6, Leiden, The Netherlands

3. Sven Blokland Aachen Janssen Vaccines & Prevention B.V

   Janssen (Netherlands)

   Affiliation as printed

   Janssen Vaccines & Prevention B.V., Archimedesweg 4-6, Leiden, The Netherlands

4. Pascale Bouchier Aachen Janssen Vaccines & Prevention B.V

   Janssen (Netherlands)

   Affiliation as printed

   Janssen Vaccines & Prevention B.V., Archimedesweg 4-6, Leiden, The Netherlands

5. Richard Voorzaat Aachen Janssen Vaccines & Prevention B.V

   Janssen (Netherlands)

   Affiliation as printed

   Janssen Vaccines & Prevention B.V., Archimedesweg 4-6, Leiden, The Netherlands

6. Tina Ritschel Aachen Janssen Vaccines & Prevention B.V

   Janssen (Netherlands)

   Affiliation as printed

   Janssen Vaccines & Prevention B.V., Archimedesweg 4-6, Leiden, The Netherlands

7. Mark J. G. Bakkers Aachen Janssen Vaccines & Prevention B.V

   Janssen (Netherlands)

   Affiliation as printed

   Janssen Vaccines & Prevention B.V., Archimedesweg 4-6, Leiden, The Netherlands

8. Ludovic L. R. Renault Aachen NeCEN

   Leiden University

   Affiliation as printed

   NeCEN, Leiden University, Einsteinweg 55, Leiden, The Netherlands

9. Johannes P. M. Langedijk corresponding Aachen Janssen Vaccines & Prevention B.V

   Janssen (Netherlands)

   Affiliation as printed

   Janssen Vaccines & Prevention B.V., Archimedesweg 4-6, Leiden, The Netherlands. hlangedi@its.jnj.com

   Janssen Vaccines & Prevention B.V., Archimedesweg 4-6, Leiden, The Netherlands