SARS Spike (1-53, 90-115, 171-205)
Description
Receptor Binding and Immune Interactions
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The NTD is distinct from the receptor-binding domain (RBD) but contributes to sialic acid binding in some coronaviruses, facilitating initial attachment to host cells .
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Residues 90-115 and 171-205 contain linear epitopes identified in convalescent sera, suggesting roles in immune recognition .
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Mutations in analogous regions of SARS-CoV-2 (e.g., NTD deletions in Alpha/B.1.1.7) enhance immune evasion and transmissibility .
Diagnostic and Therapeutic Development
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Recombinant protein fragments (e.g., HEK293-derived SARS-CoV-1 Spike S1, residues 1-666) are used to study antibody responses and vaccine efficacy .
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Peptide microarrays covering these regions identified immunodominant epitopes in COVID-19 patients, aiding diagnostics design .
Key Studies
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Epitope Mapping: A 2020 study using 1,051 patient sera revealed strong antibody responses to NTD epitopes, including residues 1-53 and 90-115 .
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Structural Dynamics: Cryo-EM analyses show that NTD flexibility (residues 171-205) influences RBD accessibility and ACE2 binding .
Comparative Analysis with SARS-CoV-2
While SARS-CoV-1 and SARS-CoV-2 share structural homology, their NTDs exhibit divergent evolutionary pressures:
Future Directions
Product Specs
Purified by proprietary chromatographic technique.
Immunoreactive with sera of SARS-infected individuals.
Product Science Overview
The SARS-Associated Coronavirus (SARS-CoV) spike protein is a crucial component of the virus’s structure, playing a significant role in its ability to infect host cells. The recombinant form of this protein, specifically the segments spanning amino acids 1-53, 90-115, and 171-205, has been extensively studied for its potential applications in research and therapeutic development.
The spike (S) protein of SARS-CoV is a transmembrane glycoprotein that facilitates the virus’s entry into host cells. It is composed of two subunits, S1 and S2. The S1 subunit contains the receptor-binding domain (RBD), which is responsible for binding to the host cell receptor, angiotensin-converting enzyme 2 (ACE2). The S2 subunit mediates the fusion of the viral and host cell membranes, allowing the viral genome to enter the host cell .
The recombinant spike protein segments (1-53, 90-115, 171-205 a.a.) are produced in E. coli and are fused to a His-tag for purification purposes . These segments are chosen for their relevance in the protein’s structure and function, particularly in the context of antibody recognition and vaccine development.
- Vaccine Development: The spike protein is a primary target for vaccine development due to its critical role in viral entry. Recombinant forms of the spike protein are used to elicit an immune response in the host, providing protection against the virus.
- Diagnostic Tools: Recombinant spike proteins are used in serological assays to detect antibodies against SARS-CoV in patient samples. This is essential for diagnosing past infections and understanding the spread of the virus.
- Therapeutic Research: The spike protein is also a target for therapeutic interventions, such as monoclonal antibodies that can neutralize the virus by blocking its ability to bind to ACE2.
Studies have shown that the spike protein’s interaction with ACE2 is a key determinant of the virus’s infectivity and pathogenicity . Structural analyses have revealed that specific mutations in the spike protein can enhance its binding affinity to ACE2, potentially increasing the virus’s transmissibility . Understanding these interactions is crucial for developing effective vaccines and therapeutics.
