Recombinant Staphylococcus aureus ESAT-6 secretion system extracellular protein A (esxA) is produced in E.coli and contains the complete sequence from amino acids 1 to 97. The protein features an N-terminal 6xHis-SUMO tag, which aids in purification and detection processes. SDS-PAGE analysis indicates a purity level exceeding 90%, making this product suitable for research applications. Low endotoxin levels during preparation appear to ensure compatibility with most experimental setups.
The ESAT-6 secretion system extracellular protein A (esxA) represents a key component of the Staphylococcus aureus secretion machinery. This protein likely plays a significant role in transporting and secreting proteins across the bacterial membrane—a process that seems essential for bacterial virulence and survival. Research into this protein may prove vital for understanding bacterial pathogenicity and could contribute to developing new antibacterial strategies.
Potential Applications
Note: The applications listed below are based on what we know about this protein's biological functions, published research, and experience from experts in the field. However, we haven't fully tested all of these applications ourselves yet. We'd recommend running some preliminary tests first to make sure they work for your specific research goals.
Staphylococcus aureus EsxA is a bacterial virulence factor that requires specific folding and dimerization for its pore-forming activity and interaction with host cells. The E. coli expression system is compatible with this bacterial protein, increasing the likelihood of correct folding. The SUMO tag may enhance solubility and proper folding. However, the large N-terminal SUMO tag (∼15 kDa) may sterically interfere with EsxA's functional domains or dimerization interfaces. While the protein may be soluble and partially folded, the probability of correct dimerization and full functional activity requires experimental validation.
1. Antibody Development and Immunological Studies
This recombinant EsxA serves as an excellent immunogen for generating antibodies against S. aureus EsxA. The full-length sequence ensures comprehensive coverage of the epitope. The SUMO tag facilitates purification and immunization procedures. These antibodies will be valuable for detecting EsxA in bacterial cultures and infection studies.
2. Protein-Protein Interaction Studies
Protein-protein interactions require a precise quaternary structure that may be compromised by the large tag. The protein's dimerization must be experimentally validated. If correctly folded and dimerized, EsxA could identify physiological partners within the ESAT-6 secretion system. However, the SUMO tag may sterically hinder interaction interfaces or prevent proper dimerization. Results require validation with tag-free protein and complementary methods.
3. Biochemical Characterization and Stability Studies
This is the essential first step to assess protein quality. Techniques like size-exclusion chromatography with multi-angle light scattering (SEC-MALS) can determine oligomeric state and dimer formation. Circular dichroism can be used to analyze secondary structure and thermal stability. These analyses provide crucial data about the protein's folding state and oligomerization capability of the protein itself, not the native Staphylococcus aureus EsxA.
4. ELISA-Based Detection System Development
This protein is well-suited as a standard for quantitative ELISA to detect anti-EsxA antibodies. The assay depends on antibody binding to linear epitopes, so the protein's folding state is less critical. The His-SUMO tag enables consistent immobilization for reliable detection.
Final Recommendation & Action Plan
This recombinant EsxA has strong potential for immunological applications but requires validation of dimerization and folding before reliable use in interaction studies. The immediate priority is Application 3 (Biochemical Characterization) to assess dimer formation via SEC-MALS and validate folding quality. If proper dimerization is confirmed, proceed cautiously with Application 2 (Interaction Studies). Applications 1 and 4 (Antibody Development and ELISA) can proceed immediately. Consider SUMO tag removal for critical functional studies. For reliable pore-forming or host-interaction studies, validation with native EsxA from S. aureus is recommended. This systematic approach ensures appropriate use based on functional validation.
