REAGENT or RESOURCE	SOURCE	IDENTIFIER
Antibodies
Horseradish peroxidase-conjugated anti-human IgG	Jackson ImmunoResearch	Cat# 109-035-088; RRID: AB_2337584
Mouse anti-human IgG1	Southern biotech	Cat# SB-9054-05; RRID: AB_2796627
Mouse anti-human IgG2	Southern biotech	Cat# SB-9060-05; RRID: AB_2796633
Mouse anti-human IgG3	ThermoFisher	Cat# MH1732; RRID: AB_2539713
Mouse anti-human gG4	Southern biotech	Cat# SB-9200-05; RRID: AB_2796691
Biological samples
Human plasma from COVID19 patients	Isolated from patients in Ichilov and Sheba medical centers	Helsinky: #0262-20-TLV, #7287-20), WIS IRB #1280
Human plasma from Pfizer–BioNTech COVID-19 (Tozinameran) Vaccinated donors	In house, Isolated from volunteers	WIS IRB #1280
Chemicals, peptides, and recombinant proteins
TMB One Component Substrate	Bethyl laboratories, INC	Cat# TOA-48156708
Pierce NHS-Activated Magnetic Beads	ThermoFisher	Cat# TS88832
protein G Sepharose 4 Fast Flow beads	GE Healthcare	Cat# 17-0618-05
IgGs Elution Buffer	ThermoFisher	Cat# 21009
The SARS-CoV-2 (2019-nCoV) Nucleoprotein His-tag protein	Sino biological	Cat# 40588-V08B
HisPur Ni-NT resin	ThermoFisher	Cat# TS-88222
imidazole	Sigma-Aldrich	Cat# I5513
the human recombinant receptors FcγRIIA	Sino Biological	Cat# 10374-H08H
the human recombinant receptors FcγRIIB	Sino Biological	Cat# 10259-H08H
the human recombinant receptors FcγR	Sino Biological	Cat# 10389-H08H
C1q	Sigma Aldrich	Cat# C1740
Nonident P40 Substitute (GEPAL)	Sigma Aldrich	Cat# CA-630
TopTip Borate p10	Glygen Corp	https://www.glysci.com/TopTip/
Critical commercial assays
Pierce Direct magnetic IP/Co-IP kit	ThermoFisher	Cat# 88828
Deposited data
Mass spectrometry data	This paper	https://www.ebi.ac.uk/ Project accession: PXD029321
Experimental models: cell lines
Expi293 Cells	ThermoFisher	Cat# A14527
Recombinant DNA
hexahistidine-tagged SARS-CoV-2 RBD construct	F. Krammer	Icahn School of Medicine at Mount Sinai
The SARS-CoV-2 (2019-nCoV) Nucleoprotein His-tag plasmid	Sino Biological	VG40588-CH
Software and algorithms
Graphpad Prism Prism 9.2.0	GraphPad Prism	RRID: SCR_002798
Rstudio (version 1.3.1093)	R studio	https://www.rstudio.com/
Byonic	Protein metrics	https://proteinmetrics.com/byos/
Skyline	McCoss Lab,Univeristy of Washington	https://skyline.ms/project/home/software/Skyline/begin.view