PT  - JOURNAL ARTICLE
AU  - Nyström, Sofie
AU  - Hammarström, Per
TI  - Amyloidogenesis of SARS-CoV-2 Spike Protein
AID  - 10.1101/2021.12.16.472920
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.12.16.472920
4099  - http://biorxiv.org/content/early/2021/12/17/2021.12.16.472920.short
4100  - http://biorxiv.org/content/early/2021/12/17/2021.12.16.472920.full
AB  - SARS-CoV-2 infection is associated with a surprising number of morbidities. Uncanny similarities with amyloid-disease associated blood coagulation and fibrinolytic disturbances together with neurologic and cardiac problems led us to investigate the amyloidogenicity of the SARS-CoV-2 Spike protein (S-protein). Amyloid fibril assays of peptide library mixtures and theoretical predictions identified seven amyloidogenic sequences within the S-protein. All seven peptides in isolation formed aggregates during incubation at 37°C. Three 20-amino acid long synthetic Spike peptides (sequence 191-210, 599-618, 1165-1184) fulfilled three amyloid fibril criteria: nucleation dependent polymerization kinetics by ThT, Congo red positivity and ultrastructural fibrillar morphology. Full-length folded S-protein did not form amyloid fibrils, but amyloid-like fibrils with evident branching were formed during 24 hours of S-protein co-incubation with the protease neutrophil elastase (NE) in vitro. NE efficiently cleaved S-protein rendering exposure of amyloidogenic segments and accumulation of the peptide 193-202, part of the most amyloidogenic synthetic Spike peptide. NE is overexpressed at inflamed sites of viral infection and at vaccine injection sites. Our data propose a molecular mechanism for amyloidogenesis of SARS-CoV-2 S-protein in humans facilitated by endoproteolysis. The potential implications of S-protein amyloidogenesis in COVID-19 disease associated pathogenesis and consequences following S-protein based vaccines should be addressed in understanding the disease, long COVID-19, and vaccine side effects.Competing Interest StatementThe authors have declared no competing interest.CNScentral nervous systemSARS-CoV-2Severe Acute Respiratory Syndrome Coronavirus-2S-proteinSpike proteinThT,Thioflavin TCN-PiBCyano-Pittsburgh compound BTEMtransmission electron microscopyDSFDifferential scanning fluorimetry