REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
6D3 IgG2b	Stony Brook University, New York	N/A
InVivoMab mouse IgG2b isotype control	BioXcell	Cat#BE0086
mouse anti-dsRNA [J2] antibody	Absolute Antibody	Cat#Ab01299-2.0
Goat anti-Mouse IgG (H+L) Cross-Adsorbed Secondary Antibody, Alexa Fluor 555	Thermo Fisher Scientific	Cat#A21422
Bacterial and Virus Strains
SARS-CoV-2	BEI Resources of National Institute of Allergy and Infectious Diseases (NIAID)	Isolate USA-WA1/2020
Chemicals, Peptides, and Recombinant Proteins
DAPI (4',6-Diamidino-2-Phenylindole, Dihydrochloride)	Life Technologies	Cat#D1306
Penicillin-Streptomycin (10,000 U/mL)	Gibco	Cat#15140122
Deposited Data
Antibody-Spike complexes see Table 1	Protein Data Bank (PDB)	N/A
SARS-CoV-2 Spike with one chain in up state	(Wrapp et al., 2020)	PDB: 6VSB
SARS-CoV-2 Spike in down state	(Walls et al., 2020)	PDB: 6VXX
HCoV-OC43 Spike in down state	(Tortorici et al., 2019)	PDB: 6NZK
Furin	(Dahms et al., 2016)	PDB: 5JMO
SARS-CoV-2 glycosylated Spike protein model	(Woo et al., 2020)	https://charmm-gui.org/?doc=archive&lib=covid19
Antibodies 6D3 and 14G8 bound to SEB	(Dutta et al., 2015)	PDB: 4RGN
Antibody 20B1 bound to SEB	(Dutta et al., 2015)	PDB: 4RGM
Human TMPRSS2 homology model	This paper	https://zenodo.org/record/4667694#.YGz7DOhKhPZ
SARS-CoV-2 Spike bound to TMPRSS2	This paper	https://zenodo.org/record/4667694#.YGzUgOhKhPY
SARS-CoV-2 Spike bound to furin	This paper	https://zenodo.org/record/4667694#.YGzUgOhKhPY
Ab 6D3 bound to SARS-CoV-2 Spike in one up state	This paper	https://zenodo.org/record/4667694#.YGzUgOhKhPY
Ab 6D3 bound to SARS-CoV-2 Spike in down state	This paper	https://zenodo.org/record/4667694#.YGzUgOhKhPY
Ab 6D3 bound to HCoV-OC43 Spike in down state	This ppaer	https://zenodo.org/record/4667694#.YGzUgOhKhPY
Experimental Models: Cell Lines
Vero-E6	ATCC	Cat#CRL-1586
Software and Algorithms
ClusPro	(Kozakov et al., 2017)	https://cluspro.bu.edu/
SWISS-MODEL	(Waterhouse et al., 2018)	https://swissmodel.expasy.org/interactive
PRODIGY	(Xue et al., 2016)	https://bianca.science.uu.nl//prodigy/
PyMOL	(DeLano, 2002)	https://pymol.org/2/
HADDOCK 2. 4	(Van Zundert et al., 2016)	https://bianca.science.uu.nl/haddock2.4/
Clustal Omega	(Sievers et al., 2011)	https://www.ebi.ac.uk/Tools/msa/clustalo/
Prism	GraphPad	https://www.graphpad.com/scientific-software/prism/
BZ-X700 Analysis Software	Keyence	https://www.keyence.com/landing/microscope/lp_fluorescence.jsp
Other
Eagle's Minimum Essential Medium (MEM)	Corning	Cat#10009CV
Regular Fetal Bovine Serum	Corning	Cat#35010CV
Goat Serum	Cell Signaling	Cat#5425S
Normal Donkey Serum	Jackson ImmunoResearch	Cat#017-000-121
BZ-X710 Fluorescence Microscope	Keyence	Model#BZ-X710