| Field | Specification |
|---|---|
| Mfr No | |
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| Alternative Names | Genome polyprotein [Cleaved into: P1; Capsid protein VP0; VP4-VP2); Capsid protein VP4; P1A; Virion protein 4); Capsid protein VP2; P1B; Virion protein 2); Capsid protein VP3; P1C; Virion protein 3); Capsid protein VP1; P1D; Virion protein 1); P2; Protease 2A; P2A; EC 3.4.22.29; Picornain 2A; Protein 2A); Protein 2B; P2B); Protein 2C; P2C; EC 3.6.1.15); P3; Protein 3AB; Protein 3A; P3A); Viral protein genome-linked; VPg; Protein 3B; P3B); Protein 3CD; EC 3.4.22.28); Protease 3C; EC 3.4.22.28; Picornain 3C; P3C); RNA-directed RNA polymerase; RdRp; EC 2.7.7.48; 3D polymerase; 3Dpol; Protein 3D; 3D)] |
| Conjugate | |
| Endotoxin Level | |
| Expression System | |
| Form | Liquid or Lyophilized powder |
| Function | |
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| Reconstitution | |
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| UniProt # |
Overview
Recombinant Human rhinovirus A serotype 89 Genome polyprotein, partial is a recombinant protein reagent for research-use applications such as assay development, binding studies, and mechanistic experiments. It corresponds to POLG (Human rhinovirus A serotype 89 (strain 41467-Gallo) (HRV-89)) and is intended for RUO workflows where a defined protein standard or functional input is needed.
Key elements and design rationale
- Expression system: Yeast (expression context can influence folding and PTMs).
- Expression region: 575-866aa (region choice can affect activity and binding readouts).
- Conjugate(s)/tag: N-terminal 6xHis-tagged (can support detection or purification depending on format).
- Molecular weight: 34.6 kDa (useful for interpreting gel migration and size-exclusion profiles).
When comparing results across assays, consider that expression system and expressed region can alter glycosylation, disulfide formation, and oligomerization state, which may shift apparent potency or binding behavior in vitro.
Biological background
Capsid protein VP1: Forms an icosahedral capsid of pseudo T=3 symmetry with capsid proteins VP2 and VP3. The capsid is 300 Angstroms in diameter, composed of 60 copies of each capsid protein and enclosing the viral positive strand RNA genome. Capsid protein VP1 mainly forms the vertices of the capsid. Capsid protein VP1 interacts with host cell receptor to provide virion attachment to target host cells. This attachment induces virion internalization. Tyrosine kinases are probably involved in the entry process. After binding to its receptor, the capsid undergoes conformational changes. Capsid protein VP1 N-terminus (that contains an amphipathic alpha-helix) and capsid protein VP4 are externalized. Together, they shape a pore in the host mbrane through which viral genome is translocated to host cell cytoplasm. After genome has been released, the channel shrinks .Capsid protein VP2: Forms an icosahedral capsid of pseudo T=3 symmetry with capsid proteins VP2 and VP3. The capsid is 300 Angstroms in diameter, composed of 60 copies of each capsid protein and enclosing the viral positive strand RNA genome .Capsid protein VP3: Forms an icosahedral capsid of pseudo T=3 symmetry with capsid proteins VP2 and VP3. The capsid is 300 Angstroms in diameter, composed of 60 copies of each capsid protein and enclosing the viral positive strand RNA genome .Capsid protein VP4: Lies on the inner surface of the capsid shell. After binding to the host receptor, the capsid undergoes conformational changes. Capsid protein VP4 is released, Capsid protein VP1 N-terminus is externalized, and together, they shape a pore in the host mbrane through which the viral genome is translocated into the host cell cytoplasm. After genome has been released, the channel shrinks .Capsid protein VP0: Component of immature procapsids, which is cleaved into capsid proteins VP4 and VP2 after maturation. Allows the capsid to rain inactive before the maturation step .Protein 2A: Cysteine protease that cleaves viral polyprotein and specific host proteins. It is responsible for the cleavage between the P1 and P2 regions, first cleavage occurring in the polyprotein. Cleaves also the host translation initiation factor EIF4G1, in order to shut down the capped cellular mRNA translation. Inhibits the host nucleus-cytoplasm protein and RNA trafficking by cleaving host mbers of the nuclear pores .Protein 2B: Plays an essential role in the virus replication cycle by acting as a viroporin. Creates a pore in the host reticulum endoplasmic and as a consequence releases Ca2+ in the cytoplasm of infected cell. In turn, high levels of cyctoplasmic calcium may trigger mbrane trafficking and transport of viral ER-associated proteins to viroplasms, sites of viral genome replication .Protein 2C: Induces and associates with structural rearrangents of intracellular mbranes. Displays RNA-binding, nucleotide binding and NTPase activities. May play a role in virion morphogenesis and viral RNA encapsidation by interacting with the capsid protein VP3 .Protein 3AB: Localizes the viral replication complex to the surface of mbranous vesicles. Together with protein 3CD binds the Cis-Active RNA Elent (CRE) which is involved in RNA synthesis initiation. Acts as a cofactor to stimulate the activity of 3D polymerase, maybe through a nucleid acid chaperone activity .Protein 3A: Localizes the viral replication complex to the surface of mbranous vesicles. It inhibits host cell endoplasmic reticulum-to-Golgi apparatus transport and causes the dissassbly of the Golgi complex, possibly through GBF1 interaction. This would result in depletion of MHC, trail receptors and IFN receptors at the host cell surface .Viral protein genome-linked: acts as a primer for viral RNA replication and rains covalently bound to viral genomic RNA. VPg is uridylylated prior to priming replication into VPg-pUpU. The oriI viral genomic sequence may act as a tplate for this. The VPg-pUpU is then used as primer on the genomic RNA poly(A) by the RNA-dependent RNA polymerase to replicate the viral genome. VPg may be roved in the cytoplasm by an unknown enzyme termed "unlinkase". VPg is not cleaved off virion genomes because replicated genomic RNA are encapsidated at the site of replication .Protein 3CD: Is involved in the viral replication complex and viral polypeptide maturation. It exhibits protease activity with a specificity and catalytic efficiency that is different from protease 3C. Protein 3CD lacks polymerase activity. The 3C domain in the context of protein 3CD may have an RNA binding activity .Protease 3C: cleaves host DDX58/RIG-I and thus contributes to the inhibition of type I interferon production. Cleaves also host PABPC1 .RNA-directed RNA polymerase: Replicates the viral genomic RNA on the surface of intracellular mbranes. May form linear arrays of subunits that propagate along a strong head-to-tail interaction called interface-I. Covalently attaches UMP to a tyrosine of VPg, which is used to prime RNA synthesis. The positive stranded RNA genome is first replicated at virus induced mbranous vesicles, creating a dsRNA genomic replication form. This dsRNA is then used as tplate to synthesize positive stranded RNA genomes. ss+RNA genomes are either translated, replicated or encapsidated ..
Research relevance and current trends
- Reagent standardization: using recombinant proteins as reference materials for quantitative calibration and cross-study comparability.
- Interaction-focused studies: mapping binding partners, affinity changes, and structure–function relationships across variants or domains.
- Multi-omic readouts: combining recombinant perturbations with transcript, protein, and functional endpoints to connect mechanism to phenotype.
Common research applications
- Assay development and validation: use as a defined input or standard where protein identity is required.
- Binding studies: evaluate interaction strength and specificity using plate-based or biophysical formats.
- Cell-response profiling: add protein to cultured cells and interpret downstream marker changes with appropriate controls.
Interpretation is most robust when signal changes are evaluated relative to matched controls (buffer-only, unrelated protein controls, or pathway controls) and when readouts are compared across dose and time.
Notes for experimental interpretation
- Isoforms and PTMs can influence binding and activity; ensure the expressed region and expression system match your experimental needs.
- Species differences may affect receptor binding or antibody recognition; confirm species/source alignment with your model.
- Use concept-level controls such as negative controls (no protein), matrix controls, or orthogonal readouts to support conclusions.
What is protein expression and purification?
Why is there no/low protein expression?
b. Rare codons. You should optimize codons, use strains supplementing rare codons, induce at lower temperature or grow in poor media.
c. Protein toxicity. You should use promoters with tighter regulation or lower plasmid copy number. Use pLysS/pLysE bearing strains in T7-based systems or strains that are better for the expression of toxic proteins. Start induction at high OD and shorten induction time. Add glucose when using expression vectors containing lac-based promoters.
How to avoid inclusion bodies and improve soluble expression?
b. Incorrect disulfide bond formation. You should add fusion partners, including thioredoxin, DsbA, DsbC. Clone in a vector containing secretion signal peptide to cell periplasm. Use gamiB (DE3)strains with oxidative cytoplasmic environment. Lower inducer concentration and induction temperature.
c. Incorrect folding. You should use a fusion partner. Co-express with molecular chaperones. Use strains with cold-adapted chaperones. Supplement media with chemical chaperones and cofactors. Reduce the inducer concentration and add fresh media. Induce for a shorter time at low temperature.
Why is the molecular weight of protein smaller than the predicted?
b. Imbalanced translation process of fusion protein. You should change another fusion tag or move fusion tag to C-terminal. You should induce for a shorter time at low temperature or change to poor media.
c. Protein degradation. You should replace specific protease sites. Use protease deficient strains. Induce at high OD. You should induce for a shorter time at low temperature or use protease inhibitors when breaking cells.
Why is the actual band size different from the predicted?
b. Post-translational cleavage. Many proteins are synthesized as pro-proteins, and then cleaved to give the active form.
c. Splice variants. Alternative splicing may create different sized proteins from the same gene.
d. Relative charge. The composition of amino acids have different relative charge which will affect the electrophoretic mobility.
e. Multimers such as dimerisation of a protein. This is usually prevented in reducing conditions, although strong interactions can result in the appearance of higher bands.
f. Protein structure such as disulfide bond, protein secondary structure or protein 3D structure formation.
g. Hydrophobic proteins, such as transmembrane proteins, may have difficulties in migrating into the gel, and thus resulting in different multi-banded patterns.
How to express a protein with bioactivity? Why is the protein inactive?
a. Low solubility of the protein. You should fuse desired protein to a fusion partners and lower temperature.
b. Lack of essential post translational modification. You should change another expression system.
c. Incomplete folding. You should use a fusion partner and use strains with cold-adapted chaperones. Co-express with molecular chaperones at lower temperature. Monitor disulfide bond formation and allow further folding in vitro.
d. Mutations in cDNA. You should sequence plasmid before and after induction or use a recA− strain to ensure plasmid stability. Transform E. coli before each expression round.
Why are our protein products almost invisible in pipes?
Tips: Before opening the lid, we recommend to centrifuge in a small centrifuge for 20-30 seconds firstly to ensure that the contents are on the bottom of the tube. Our quality control steps ensure that the amount of protein contained in each tube is accurate, although sometimes you can’t see the protein powder, but the protein content in the tube is still very accurate.
How is the protein purified? Is the purity guaranteed?
Although we guarantee a minimum purity standard of >85%, some of the proteins we prepared have a purity of 95% or even 97%.
How should I reconstitute and store the products?
As for short-term storage or usage, please use sterile deionized water to completely reconstitute proteins to 0.1-1.0 mg/mL. Aliquot after 10-15 minutes if needed and store at 4℃.
As for long-term storage, the cytokines or recombinant proteins are recommended to add 5-50% of glycerol (final concentration) and aliquot for long-term storage at -20℃/-80℃. Our default final concentration of glycerol is 50%. Customers could use it as reference.
What types of tags do you use for fusion?
What is the impact of a given tag type and any potential biological activity of the protein?
Can you remove the endotoxin?
Can you offer aseptic manufacture processing?
How to determine species cross-reactivity of cytokines?
b. Many mouse cytokines may also have effect on human cells, however, the activity may be lower than the corresponding human cytokines.
c. One of the few human cytokines will be more active than corresponding mouse cytokines when acting on mouse cells, such as IL-7.
d. Interferon, GM-CSF, IL-3 and IL-4 and other cytokines are species-specific and almost have no activity on non-homologous cells.
e. In contrast, fibroblast growth factor (FGF) and neurotrophin are highly conserved and both have good activity on cells of different species.
What is the general preservative? Which kind of preservative do you usually add?
What is the general protectant? What kind of protectant do you usually add?
Can’t Find What You’re Looking For? We can help you source the best match or customize a recombinant protein solution for your study. Options may include species (human/mouse/rat), protein region/domain (full-length vs fragment), tag or label (His/GST/FLAG/biotin/fluorescent), expression system (E. coli/HEK293/insect), purity grade, formulation (buffer, carrier-free, glycerol-free), activity/functional validation (binding or enzymatic assays), endotoxin level (low-endotoxin for cell-based work), mutants/variants (point mutations, isoforms), and bulk or custom packaging. Click Talk to a Scientist to submit a request form, email us at support@biohippo.com, or explore our Research Services for additional support. Our team will be in contact with you shortly.
