COVID-19 Proteins

Recombinant SARS-CoV-2 Proteins

The nucleocapsid protein (N-protein) and spike protein (S-protein) are encoded by all coronaviruses, including the SARS-CoV-2 that was first detected in Wuhan City, China, in December 2019. Both recombinant forms of these proteins are now available from RayBiotech to advance infectious disease research (Figures 1 & 2).

Nucleocapsid Protein (N-Protein)

The nucleocapsid protein (N-protein) is a structural protein that binds to the coronavirus RNA genome, thus creating a shell (or capsid) around the enclosed nucleic acid. The N-protein also 1) interacts with the viral membrane protein during viral assembly, 2) assists in RNA synthesis and folding, 3) plays a role in virus budding, and 4) affects host cell responses, including cell cycle and translation.

Nucleocapsid Protein (N-Protein)
Figure 1. N-protein domains
RBD = RNA binding domain; IDR = intrinsically disordered region; SR = serine-arginine-rich; NLS = nuclear localization signal.

Spike Protein (S-Protein)

The spike protein (S-protein) performs two primary tasks that aid in host infection: 1) mediates the attachment between the virus and host cell surface receptors, and 2) facilitates viral entry into the host cell by assisting in the fusion of the viral and host cell membranes.

Spike Protein (S-Protein)
Figure 2. SARS-CoV-2 Spike (S) protein domains. Spike proteins have two subunits (S1, S2). In S1 subunit, the RBD (receptor binding domain) can bind to human ACE2 (Products 230-30165, 230-30177); CendR domain can bind to human NRP-1 b1b2 domain (Products 230-30176, 230-30178). The numbers below the domains show the amino acid position.

Thrombosis-related Protein Biomarkers

The inflammation associated with SARS-CoV-2 infection can cause disseminated intravascular coagulopathy (DIC), leading to obstruction of the blood vessels of lung, heart and kidneys. Initially, DIC in COVID-19 patients presents with abnormalities in prothrombin time, partial thromboplastin time, and platelet counts.

COVID-related Endogenous Proteins

Angiotensin I Converting Enzyme 2 (ACE2) is an endogenous receptor that is required for SARS-CoV-2 viral entry. Neuropilin-1 (NRP1) assists in SARS-CoV-2 entry.


Products

Recombinant N Protein:

Catalog # Protein Domain Purification Expression Host Expression Region Tag MW (kDa)
230-30164 Full length Purified HEK293 Cell Met1 - Ala419 C-terminal His-tag ∼55 kDa
230-01104 Purified E.coli Met1 - Ala419 N-terminal His-tag ∼50 kDa
230-20409 Unpurified HEK293 Cell Met1 - Ala419 C-terminal His-tag ∼50 kDa
244-10002 Purified Insect Cells   C-terminal 47

Recombinant Spike Subunit 1 (S1) and Subunit 2 (S2) Chimeric Protein:

Catalog # Protein Domain Purification Expression Host Expression Region Tag MW (kDa)
244-10001 S1 + S2 Purified Insect Cells   C-terminal 135

Recombinant Spike Subunit 1 (S1) Protein, full length:

Catalog # Protein Domain Purification Expression Host GenBank Accession # Expression Region Tag MW (kDa)
230-30161 Full length Purified HEK293 Cell QHD43416 Val16 - Gln690 C-terminal His-tag ∼120 kDa
230-01101 Full length Purified E.coli QHD43416 Val16 - Gln690 N-terminal His-tag ∼75 kDa
230-20407 Full length Unpurified HEK293 Cell QHD43416 Val16 - Gln690 C-terminal His-tag ∼120 kDa

Recombinant Spike Subunit 1 (S1) Protein, RBD domain, wild type:

Catalog # Protein Domain Purification Expression Host GenBank Accession # Expression Region Tag MW (kDa)
230-30162 RBD Purified HEK293 Cell QHD43416 Arg319 - Phe541 C-terminal His-tag ∼30 kDa
230-30166 RBD Purified HEK293 Cell QHD43416 Arg319 - Phe541 C-terminal Fc-tag ∼65 kDa
230-01102 RBD Purified E.coli QHD43416 Arg319 - Phe541 N-terminal His-tag ∼25 kDa
230-20405 RBD Unpurified HEK293 Cell QHD43416 Arg319 - Phe541 C-terminal Fc-tag ∼65 kDa
230-20406 RBD Unpurified HEK293 Cell QHD43416 Arg319 - Phe541 C-terminal His-tag ∼25 kDa

Recombinant Spike Subunit 1 (S1) Protein, RBD domain, mutants:

Catalog # Protein Domain Purification Expression Host GenBank Accession # Expression Region Tag MW (kDa)
230-30157 N331Q RBD mutant Purified HEK293 Cell QHD43416 Arg319 - Phe541 (N331Q mutant) C-terminal His-tag ∼30 kDa

Recombinant Spike Subunit 1 (S1) Protein, CendR domain:

Catalog # Protein Domain Purification Expression Host GenBank Accession # Expression Region Tag MW (kDa)
230-30179 C-terminal CendR domain Purified HEK293 Cell QHD43416 Asn542 - Arg685 N-terminal His-tag ∼25-35 kDa
230-30180 C-terminal CendR domain Purified HEK293 Cell QHD43416 Asn542 - Arg685 C-terminal Fc-tag ∼55 kDa

Recombinant Spike Subunit 2 (S2) Protein:

Catalog # Protein Domain Purification Expression Host Expression Region Tag MW (kDa)
230-01103 Full length Purified E.coli Met697 - Pro1213 N-terminal His-tag ∼58 kDa
230-30163 Purified HEK293 Cell Met697 - Pro1213 C-terminal His-tag ∼80 kDa
230-20408 Unpurified HEK293 Cell Met697 - Pro1213 C-terminal His-tag ∼60 kDa

Recombinant Membrane Protein:

Catalog # Protein Domain Purification Expression Host Expression Region Tag MW (kDa)
230-01124NEW C-terminal domain Purified E. coli Arg101-Gln222 N-terminal His-tag ∼15 kDa

For help identifying the right protein for your research, please contact our technical support team at [email protected] or (888) 494-8555.


Analysis Images

COVID-19 Proteins SDS-PAGE
Figure 4. SDS-PAGE analysis of the purified recombinant SARS-CoV-2 target proteins.
Figure 5. SDS-PAGE analysis of the purified recombinant SARS-CoV-2 target proteins and human ACE2. Lane 1: Protein standard ladder (kDa); Lane 2: Untreated protein under reducing conditions; Lane 3: Treated protein with deglycosylation enzymes under native conditions; Lane 4: Treated protein with deglycosylation enzymes under reducing conditions.
COVID-19 Proteins Western Blot
Figure 6. Western blotting analysis of transfected HEK293 cells shown the secretion and overexpression of SARS-CoV-2 target proteins. The enlarged molecular weight might be due to the abundant post-translation modifications.

References

  1. A Antonopoulos, et al. Site-specific characterisation of SARS-CoV-2 spike glyocprotein receptor binding domain. Glycobiology, cwaa085 (2020).
  2. A Shajahan, et al. Deducing the N- and O- glycosylation profile of the spike protein of novel coronavirus SARS-CoV-2. Glycobiology, cwaa042 (2020).
  3. A Vojdani and D Kharrazian. Potential antigenic cross-reactivity between SARS-CoV-2 and human tissue with a possible link to an increase in autoimmune diseases. Clin Immunol. 217, 108480 (2020).
  4. F Wu, et al. A new coronavirus associated with human respiratory disease in China. Nature. 579, 265–269 (2020).
  5. J Yu, et al. Direct activation of the alternative complement pathway by SARS-CoV-2 spike protein is blocked by factor D inhibition. Blood. 2020 Sep 2;blood.2020008248 (2020).
  6. M Casasanta, et al. Structural Insights of the SARS-CoV-2 Nucleocapsid Protein. Comput Struct Biotechnol J. 18, 2174–2184 (2020).
  7. M Hoffmann, et al. SARS-CoV-2 Cell Entry Depends on ACE2 and TMPRSS2 and Is Blocked by a Clinically Proven Protease Inhibitor. Cell. 181, 1–10 (2020).
  8. M Norman, et al. Ultrasensitive high-resolution profiling of early seroconversion in patients with COVID-19. Nat Biomed Eng (2020).
  9. M Woodruff, et al. Extrafollicular B cell responses correlate with neutralizing antibodies and morbidity in COVID-19. Nature Immunology (2020).
  10. N Dong, et al. Genomic and protein structure modelling analysis depicts the origin and infectivity of 2019-nCoV, a new coronavirus which caused a pneumonia outbreak in Wuhan, China. bioRxiv (2020).
  11. P Nguyen-Contant, et al. S Protein-Reactive IgG and Memory B Cell Production after Human SARS-CoV-2 Infection Includes Broad Reactivity to the S2 Subunit. mBio. 11 (5) e01991-20 (2020).
  12. W Li et al. Angiotensin-converting enzyme 2 is a functional receptor for the SARS coronavirus. Nature. 426, 450–454 (2003).