Spike S1 (B.1.351, Beta Variant), Avi-His-Tag (SARS-CoV-2) Recombinant

What it means: — this protein was produced in , determining its post-translational modification profile and application suitability.

Why it matters:

• Insect cell (Sf9) systems support post-translational processing required for kinase activity and complex formation; HEK293 supports human-like glycosylation; E. coli yields high-quantity non-glycosylated protein.
• For assays measuring native enzymatic activity (kinase, phosphodiesterase, deacetylase), the expression system directly affects the quality and accuracy of results.

How to interpret here: Verify is compatible with your assay requirements, particularly for enzyme kinetics and cell-based applications.

What it means: C-terminal Avi-His-tag — this affinity tag enables one-step chromatographic purification and can serve as a detection epitope.

Why it matters:

• GST-tag enables glutathione-affinity pull-down assays; His-tag enables IMAC and is compatible with anti-His detection; Avi-tag enables site-specific biotinylation for SPR/BLI capture or streptavidin-based assays; Fc-tag enables protein A/G purification and can extend half-life.
• Tag position (N- vs C-terminal) may affect domain accessibility — verify it does not occlude the active site or binding interface.

How to interpret here: Use anti-C antibodies for tag-based detection or capture in pull-down and ELISA assays.

What it means: ≥90% — protein purity was determined by SDS-PAGE and/or HPLC to confirm the proportion of correctly-sized target protein in the preparation.

Why it matters:

• High purity is critical for enzyme kinetics, inhibitor IC50 determinations, and SPR/BLI where contaminants would introduce signal artefacts or change the apparent kinetic parameters.
• Consistent lot-to-lot purity underpins reproducibility in hit-to-lead screening campaigns.

How to interpret here: ≥90% as determined by SDS-PAGE. Lot-specific QC data is provided on the Certificate of Analysis with each shipment.

What it means: Not applicable (BSL-1) — this protein has been classified under BSL-1 safety requirements, the lowest biosafety classification.

Why it matters:

• BSL-1 proteins pose no known risk to healthy adult laboratory workers and do not require specialised containment or personal protective equipment beyond standard laboratory practice.
• Confirms suitability for use in standard biochemistry or molecular biology laboratories without institutional BSL-2 or higher facility requirements.

How to interpret here: Standard laboratory safety practices apply. Review the product SDS/Datasheet for handling precautions specific to this compound.

What it means: This protein spans amino acids 16-685 of the target protein, covering the region used for expression and purification.

Why it matters:

• The expressed amino acid region determines which functional domains are present — catalytic domains, binding interfaces, or regulatory regions — affecting activity and assay design.
• For fragment proteins, confirm the region includes your domain of interest (active site, binding pocket, substrate site) before ordering.

How to interpret here: Amino acids 16-685 are included in this construct. Cross-reference with the UniProt domain annotation to confirm coverage of your target region.

What it means: UniProt accession P0DTC2 is the canonical identifier for this protein in the Universal Protein Resource database.

Why it matters:

• UniProt provides the canonical sequence, domain architecture, known mutations, disease associations, and curated literature — essential for designing inhibitor assays.
• Use the accession for database cross-referencing in publications and to identify known binding partners and substrate sequences.

How to interpret here: Visit uniprot.org/P0DTC2 to retrieve the full protein sequence, verify the expressed amino acid region, and review annotated active site residues and known inhibitors.