Recombinant CVB3 VP1 Protein, C-His

What it means: Target names the protein this product represents. Here the target is VP1, one of the capsid proteins of coxsackievirus B3 (CVB3) cut from the P1 region of the viral genome polyprotein.

Why it matters:

• CVB3 makes a single polyprotein; the VP1 label tells you which cleavage product this construct corresponds to, rather than the whole polyprotein.
• The accession P03313 is the entry for the whole polyprotein, so the residue range (Gly571-Phe854) is what defines the VP1 part.
• Target and Species are separate fields: VP1 is the protein, Coxsackievirus B3 is the virus it comes from.

How to interpret here: A target of VP1 with a range of Gly571-Phe854 means the product contains the VP1 chain (residues 571-851 in P03313) plus three extra residues at its C-terminal end.

Tip: When comparing VP1 products from different suppliers, compare the residue ranges and the accession, not only the target name.

What it means: Species states the organism the protein sequence comes from. For this product the species is Coxsackievirus B3 (CVB3), an enterovirus.

Why it matters:

• VP1 sequences vary between enterovirus types but also share conserved regions, so the species tells you the source sequence, not how selective the protein will be in serology.
• The accession cited by the manufacturer, UniProt P03313, is the entry for the Nancy strain of CVB3.
• Other coxsackievirus B types have their own VP1 sequences and are not covered by this product.

How to interpret here: Read Coxsackievirus B3 as the source virus of the VP1 sequence. Reactivity with antibodies raised against other enteroviruses is not characterized by the manufacturer; do not assume it in either direction.

What it means: Expression Region gives the first and last residues of the expressed sequence. The value shown here is Gly571-Phe854, numbered on the CVB3 genome polyprotein (UniProt P03313).

Why it matters:

• It tells you exactly which part of the polyprotein is present, which matters for epitope coverage and for comparing products.
• In P03313, VP1 is residues 571-851, so Gly571-Phe854 covers all of VP1 and adds three residues (852-854) from the start of protease 2A.
• The C-terminal His tag is added outside this range and is not counted in it.

How to interpret here: Gly571-Phe854 is a fragment of the CVB3 polyprotein that contains the full VP1 chain plus a three-residue C-terminal extension.

Tip: The residue numbers refer to the polyprotein, not to VP1 itself; VP1 residue 1 corresponds to polyprotein residue 571.

What it means: Expression system is the host used to produce the recombinant protein. This protein is expressed in E. coli.

Why it matters:

• E. coli gives high yield at low cost and is widely used for antigens intended for ELISA, immunization and Western blot.
• A single recombinant VP1 chain is not assembled into capsids, so epitopes that form only on intact virus particles may be absent.
• Proteins purified from E. coli can carry traces of host-cell material; the stated purity for this product is >90% as determined by SDS-PAGE.

How to interpret here: E. coli is the host behind the listed uses (ELISA, immunogen, SDS-PAGE, Western blot). For assays that depend on native capsid structure, check performance in your own system.

Tip: Endotoxin is not stated for this product; ask before using it in cell-based work.

What it means: Tag describes the fusion sequence added for purification or detection. This protein carries a C-His tag, a polyhistidine tag at the C-terminus.

Why it matters:

• A His tag allows capture on nickel or cobalt resins and detection with anti-His antibodies.
• The tag sits after the expressed range (Gly571-Phe854), at the C-terminal end of the construct.
• The manufacturer gives a predicted molecular weight of 32.53 kDa for this product; use it as a guide when reading SDS-PAGE bands.

How to interpret here: With a C-His tag you can use anti-His reagents as a control readout in ELISA or Western blot, alongside VP1-specific antibodies.

Tip: Antibodies raised against this protein may include anti-His antibodies; account for this when screening against other His-tagged proteins.

What it means: Purity states how much of the total protein runs as the expected band. This product is >90% as determined by SDS-PAGE.

Why it matters:

• Purity by SDS-PAGE describes protein composition only; it does not measure endotoxin, activity or aggregation.
• For coating ELISA plates or immunizing animals, higher purity reduces, but does not remove, signal and immune responses from host-cell proteins.
• Up to 10% of the protein may be other proteins, including host-cell proteins or truncated forms, and endotoxin is not stated, so include suitable controls.

How to interpret here: Read >90% as determined by SDS-PAGE as a minimum specification; request lot-specific data if you need an exact purity value.

Tip: Purity and identity are different questions; confirm the expected band in your own SDS-PAGE or Western blot before relying on the protein.

What it means: Form is the physical state of the product as shipped. This protein is supplied as a Lyophilized (freeze-dried) powder, lyophilized from a solution in PBS pH 7.4, 1 mM EDTA, 4% Trehalose, 1% Mannitol.

Why it matters:

• A lyophilized protein must be reconstituted before use; the stock concentration is given on the label or datasheet.
• Mix gently after adding sterile water; do not vortex or pipette up and down.
• After reconstitution, store single-use aliquots to avoid repeated freeze-thaw cycles.

How to interpret here: Plan to reconstitute the lyophilized powder in sterile water, let it sit for at least 15 minutes with gentle agitation, then aliquot for storage.

Tip: Centrifuge the vial briefly before opening so that no powder is lost from the cap or walls.