Recombinant HCoV-HKU1 Spike RBD His-tag Protein, CF

2 μg/lane of Recombinant HCoV-HKU1 Spike RBD His-tag (Catalog # 10600-CV) was resolved with SDS-PAGE under reducing (R) and non-reducing (NR) conditions and visualized by Coomassie® Blue staining, showing bands at 55-65 kDa.

• Reactivity: V
• Applications: Bioactivity
• Format: Carrier-Free

Recombinant HCoV-HKU1 Spike RBD His-tag Protein, CF Summary

• Details of Functionality: Bioassay data are not available.
• Source: Human embryonic kidney cell, HEK293-derived hcov-hku1 Spike RBD protein
  Thr310-Tyr624, with a C-terminal 6-His tag
• Accession #: Q5MQD0.1
• N-terminal Sequence: Thr310
• Protein/Peptide Type: Recombinant Proteins
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Endotoxin Note: <0.10 EU per 1 μg of the protein by the LAL method.

Applications/Dilutions

• Dilutions:
  • Bioactivity
• Theoretical MW: 36 kDa.
  Disclaimer note: The observed molecular weight of the protein may vary from the listed predicted molecular weight due to post translational modifications, post translation cleavages, relative charges, and other experimental factors.
• SDS-PAGE: 55-65 kDa, under reducing conditions

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 3 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose.
• Purity: >95%, by SDS-PAGE visualized with Silver Staining and quantitative densitometry by Coomassie® Blue Staining.
• Reconstitution Instructions: Reconstitute at 500 μg/mL in PBS.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Recombinant HCoV-HKU1 Spike RBD His-tag Protein, CF

• Spike RBD

Background

HCoV-HKU1 was identified in Hong Kong in 2005 as a new human coronavirus (1). Coronaviruses are a family of viruses that are commonly comprised of a large plus-strand RNA genome and four structural proteins: Spike protein (S), Envelope protein (E), Membrane protein (M), and Nucleocapsid protein(N). There are two well-known human coronavirus families that infect humans: Alpha coronaviruses which includes HCoV-229E and HCoV-NL63; beta coronaviruses that includes HCov-OC43, Severe Acute Respiratory Syndrome (SARS-CoV), Middle East Respirator Syndrome (MERS-CoV), and global pandemic Covid-19 (SARS-CoV2) (2). The HCoV-HKU1 Spike Protein (S Protein) is a glycoprotein that mediates membrane fusion and viral entry. As with most coronaviruses, proteolytic cleavage of the S protein generates two distinct peptides, S1 and S2 subunits. The S1 subunit is focused on attachment of the protein to the host receptor, while the S2 subunit is involved with cell fusion. The receptor binding domain (RBD) of HCoV-HKU1 is located at C‑terminal region of S1 subunit, similar to SARS‑COV, MERS‑COV and SARS‑COV2, but the RBD regions do not share significant amino acid sequence identity (3). HCoV‑HKU1 has been demonstrated to bind specifically to 9‑O‑acetylated sialic acids (9-O-Ac-Sias) attached as terminal residues to glycan chains on glycoproteins and lipids, but additional receptors remain unknown (4). HCoV‑HKU1, along with HCov-OC43, differ from other cornonaviruses in that their virions possess two types of surface projections, both involved in attachment: large "spikes" that are comprised of homotrimers of the S protein, and unique, smaller protrusions, comprised of the homodimeric hemagglutinin‑esterase (HE) (5).

1. Woo, P. et al. (2005) J. Virol.79:884.
2. Ogimi, C. et al. (2020) J Pediatric Infect Dis Soc doi: 10.1093/jpids/piaa037.
3. Qian, Z. et al. (2015) J. Virol. 89:8816.
4. Huang, X. et al. (2015) J Virol 89:7202.
5. Hulswit, R.J.G. et al. (2019) PNAS 116:2681.

Bioinformatics

• Uniprot:
  • Q5MQD0.1()