Zika Envelope
Description
The E.Coli derived Recombinant Zika Envelope protein having a Mw of 19kDa .The Zika Envelope protein is fused to a 6xHis tag at C-terminus and purified by proprietary chromatographic technique.
Product Specs
The Zika Envelope protein is supplied in a solution containing 25mM Tris-Cl and 25mM k2co3.
This Zika Envelope protein is suitable for use in various applications, including rapid diagnostic tests and immunoassays.
Q&A
Basic Research Questions
What structural features of the Zika envelope (E) protein enable viral entry?
The E protein mediates host-cell attachment and membrane fusion through three domains:
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Domain I: Central β-barrel scaffold
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Domain II: Fusion loop for endosomal membrane insertion
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Domain III: Receptor-binding interface
Key methodologies for structural analysis:
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Cryo-electron microscopy (cryo-EM) resolves full-length E protein dimers at 3.8 Å resolution .
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X-ray crystallography identifies glycan loop conformations critical for neurovirulence .
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Neutralization assays map antibody epitopes to Domain III (residues 302–329) .
How does the E protein contribute to Zika’s cross-reactivity with Dengue virus?
Cross-reactivity arises from shared epitopes in the fusion loop (Domain II) and prM protein. Experimental approaches to study this:
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ELISA binding assays quantify serum antibody cross-reactivity between Zika E and Dengue E proteins .
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Mouse passive transfer models demonstrate antibody-dependent enhancement (ADE) of Dengue infection post-Zika vaccination .
Advanced Research Questions
What experimental strategies minimize ADE risk in Zika vaccine design?
How do E protein mutations (e.g., V473M) enhance Zika’s epidemic potential?
The E-V473M mutation increases:
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Viremia levels in nonhuman primates (4.5-fold higher vs. wild-type) .
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Maternal-fetal transmission in murine models (78% placental infection rate).
Methodological validation: -
Reverse genetics introduces mutations into infectious clones.
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Competition assays quantify fitness advantages in Aedes aegypti vectors .
How do researchers resolve contradictions in glycan loop deletion studies?
Conflicting reports on glycan loop roles are addressed via:
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Mosquito oral infection assays: Deletions reduce midgut infectivity by 90% .
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Neurovirulence scoring: Paradoxically enhances neonatal mouse CNS pathology (e.g., 40% mortality vs. 10% in wild-type) due to altered E dimer conformations .
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Molecular dynamics simulations: Reveal glycan loop stabilization of Domain II quaternary structure .
Methodological Challenges
What techniques validate E protein dynamics during membrane fusion?
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Single-particle tracking: Monitors E protein conformational changes in live cells.
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pH-sensitive dyes: Trigger fusion assays at endosomal pH (5.0–6.2).
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Neutralizing antibody cocktails: Block specific fusion intermediates (e.g., ZIKV-117 targets Domain III) .
How are E protein antigenicity differences characterized across Zika lineages?
| Lineage | Antigenic Feature | Assay |
|---|---|---|
| African | Glycan loop deletions | Neutralization escape variants |
| Asian | Domain III epitope divergence | Pseudovirus neutralization (IC50 shifts ≥8-fold) |
Data integration from phylogenetic analysis and epitope binning resolves lineage-specific antibody responses .
Product Science Overview
Zika virus (ZIKV) is an arthropod-borne virus belonging to the family Flaviviridae and the genus Flavivirus. It was first identified in 1947 in a sentinel rhesus monkey in the Zika forest of Uganda . ZIKV is classified into two primary lineages: African and Asian strains, which share over 95% amino acid identity . Unlike the closely related dengue virus (DENV), which has four different serotypes, ZIKV has a single serotype .
The envelope (E) protein of ZIKV is a glycoprotein responsible for virus entry into host cells. It is the main target of neutralizing antibodies and plays a crucial role in viral invasion by facilitating receptor binding, cellular attachment, viral entry, and fusion . The E protein consists of three ectodomain structures: EDI, EDII, and EDIII . These domains are essential for the virus’s ability to infect host cells and are the focus of many vaccine development efforts.
Recombinant Zika virus envelope protein (rEZIKV) is produced using various expression systems, including mammalian cells and E. coli . The production of rEZIKV involves designing gene expression constructs to optimize the yield and functionality of the protein. For example, the C-terminus transmembrane domain of the E protein can be replaced by a rat CD4 domain to enhance expression and secretion in mammalian cells .
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Vaccine Development: The rEZIKV is a promising candidate for vaccine development. It has been shown to induce neutralizing antibodies and provide partial protection against ZIKV in immunocompetent mice . The recombinant protein can be used to develop subunit vaccines that target the E protein, potentially offering a safe and effective preventive strategy against ZIKV infection .
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Diagnostic Tools: The rEZIKV is also used in serological tests to monitor humoral immune responses. For instance, it can be employed as a coating reagent in ELISA assays to detect antibodies against ZIKV in patient sera . This application is crucial for diagnosing ZIKV infections and evaluating the efficacy of vaccines in clinical trials .
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Research: The recombinant protein is valuable for studying the molecular mechanisms of ZIKV infection and the immune response it elicits. Researchers can use rEZIKV to investigate how the virus interacts with host cells and to identify potential therapeutic targets .
