Recombinant SARS-CoV-2, RBD Protein (Delta Plus, B1.617.2.1, AY.1, India Variant)

Pricing & Details

Product. No.S952
Alternate Names
B.1.617, B.1.617.2.1, AY.1 Spike Protein, India Variant, SARS-CoV-2 Spike Protein, S1 Protein, S1 Subunit, S Protein, Receptor Binding Domain, RBD
Expression Host
Reactivity Species
Prod No.
Add to cart
S952-100 µg
100 µg
In stock
Min: 1
Step: 1
S952-500 µg
500 µg
In stock
Min: 1
Step: 1
S952-1.0 mg
1.0 mg
In stock
Min: 1
Step: 1


The three clades of lineage B.1.617 are B.1.617.1, B.1.617.2, and B.1.617.3, shown in chronological order of detection. This delta plus variant of SARS-CoV-2 (also known as B.1.617.2.1 or AY.1) emerged in India and is spreading in a number of countries.1 The RBD mutation is K417N, L452R, T478K, indicating an extra mutation which distinguishes it from the regular delta variant.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), is an enveloped, single-stranded, positive-sense RNA virus that belongs to the Coronaviridae family 2. The SARS-CoV-2 genome, which shares 79.6% identity with SARS-CoV, encodes four essential structural proteins: the spike (S), envelope (E), membrane (M), and nucleocapsid protein (N) 3. The S protein is a transmembrane, homotrimeric, class I fusion glycoprotein that mediates viral attachment, fusion, and entry into host cells 4. Each ~180 kDa monomer contains two functional subunits, S1 (~700 a.a) and S2 (~600 a.a), that mediate viral attachment and membrane fusion, respectively. S1 contains two major domains, the N-terminal (NTD) and C-terminal domains (CTD). The CTD contains the receptor-binding domain (RBD), which binds to the angiotensin-converting enzyme 2 (ACE2) receptor on host cells 4-6. Although both SARS-CoV and SARS-CoV-2 bind the ACE2 receptor, the RBDs only share ~73% amino acid identity, and the SARS-CoV-2 RBD binds with a higher affinity compared to SARS-CoV 4,7. The RBD is dynamic and undergoes hinge-like conformational changes, referred to as the “down” or “up” conformations, which hide or expose the receptor-binding motifs, respectively 8. Following receptor binding, S1 destabilizes, and TMPRSS2 cleaves S2, which undergoes a pre- to post-fusion conformation transition, allowing for membrane fusion 9,10.

Protein Details

Purified No Carrier Protein
>95% by SDS Page
Product Concentration
0.5 mg/ml
Endotoxin Level
<0.10 EU per 1 μg of the protein by the LAL method
Expression Host
Protein Accession No.
Amino Acid Sequence
State of Matter
Sterile Liquid
Predicted Molecular Mass
The predicted molecular mass is ~33 kDa.
This recombinant protein is aseptically packaged and formulated in 0.01 M phosphate buffered saline (PBS) pH 7.2 - 7.4, 150 mM NaCl with no carrier protein, potassium, calcium or preservatives added.
Storage and Stability
This recombinant protein may be stored as received at 2-8°C for up to one month. For longer term storage, aseptically aliquot in working volumes without diluting and store at -80°C. Avoid Repeated Freeze Thaw Cycles.
Country of Origin
Next Day Ice Pack
NCBI Gene Bank
Applications and Recommended Usage ?
(Quality Tested by Leinco)

References & Citations

1. Center for Disease Control and Prevention. 2020
2. Zhou, P., Yang, X., Wang, X. et al. Nature 579, 270–273. 2020.
3. Wu, F., Zhao, S., Yu, B. et al. Nature 579, 265–269. 2020.
4. Wrapp D, Wang N, Corbett KS, et al. bioRxiv. 2020.02.11.944462. 2020.
5. Walls AC, Park YJ, Tortorici MA, Wall A, McGuire AT, Veesler D. Cell. 181(2):281-292.e6. 2020.
6. Li W, Zhang C, Sui J, et al. EMBO J. 24(8):1634-1643. 2005.
7. Shang, J., Ye, G., Shi, K. et al. Nature 581, 221–224. 2020.
8. Gui M, Song W, Zhou H, et al. Cell Res. 27(1):119-129. 2017.
9. Walls AC, Tortorici MA, Snijder J, et al. Proc Natl Acad Sci U S A. 114(42):11157-11162. 2017.
10.. Hoffmann M, Kleine-Weber H, Schroeder S, et al. Cell. 181(2):271-280.e8. 2020.
Elisa Sandwich Protocol
IMPORTANT Use lot specific datasheet for all technical information pertaining to this recombinant protein.
Products are for research use only. Not for use in diagnostic or therapeutic procedures.
Cookie Policy
Leinco Technologies uses cookies to improve your experience and our website service. By continuing to browse our website, you accept our cookie policy.