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

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

Product Specifications

Product Datasheets

Carrier Free

CF stands for Carrier Free (CF). We typically add Bovine Serum Albumin (BSA) as a carrier protein to our recombinant proteins. Adding a carrier protein enhances protein stability, increases shelf-life, and allows the recombinant protein to be stored at a more dilute concentration. The carrier free version does not contain BSA.

In general, we advise purchasing the recombinant protein with BSA for use in cell or tissue culture, or as an ELISA standard. In contrast, the carrier free protein is recommended for applications, in which the presence of BSA could interfere.

Background: Spike RBD

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).

Related Research Areas

• Infectious Diseases