Recombinant Helicobacter pylori Vacuolating cytotoxin autotransporter (vacA) is expressed in E. coli, covering amino acid region 1076-1290. This partial protein carries an N-terminal 6xHis-tag that helps with purification and detection. SDS-PAGE analysis shows the product achieves greater than 90% purity, which appears suitable for research applications.
Vacuolating cytotoxin autotransporter (VacA) from Helicobacter pylori represents a key factor in bacterial pathogenicity. The protein plays an important role in how the bacterium manipulates host cellular processes. VacA promotes vacuole formation in host cells and participates in various cellular pathways. This makes it a valuable protein for studying bacterial-host interactions and immune responses.
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.
Helicobacter pylori VacA is a complex bacterial toxin that requires precise folding, oligomerization, and specific post-translational modifications for its vacuolating cytotoxin activity. The E. coli expression system can produce bacterial proteins but may not fully replicate the folding environment needed for this large, multi-domain autotransporter protein. The partial fragment (1076-1290aa) represents only a portion of the full-length toxin and may lack complete structural context. While the protein may be soluble, the probability of correct folding with functional activity is moderate but requires experimental validation.
1. Antibody Development and Immunoassay Research
This recombinant VacA fragment serves as an excellent immunogen for generating antibodies against linear epitopes of the C-terminal VacA region. The defined sequence ensures targeted antibody production. However, antibodies may not efficiently recognize conformational epitopes on the native, properly folded full-length toxin.
2. Protein-Protein Interaction Studies
Protein-protein interactions require precise tertiary structure that may be compromised in this partial fragment. A misfolded VacA fragment may exhibit non-specific binding or fail to present genuine interaction interfaces. The partial nature of the construct may lack complete binding domains. Results require validation with full-length, natively folded VacA.
3. Biochemical Characterization and Stability Studies
This is the essential first step to assess protein quality. Techniques like size-exclusion chromatography can determine oligomeric state, while circular dichroism can analyze secondary structure. These studies provide critical quality control data about the protein itself, not the native, folded VacA.
4. ELISA Development for Research Applications
This protein is well-suited as a standard for quantitative ELISA to detect anti-VacA antibodies. The assay depends on antibody binding to linear epitopes, making it reliable regardless of folding status.
Final Recommendation & Action Plan
This recombinant VacA fragment has strong potential for immunological applications but requires validation of folding before reliable use in interaction studies. The immediate priority is Application 3 (Biochemical Characterization) to assess the protein's physical properties and folding state. Applications 1 and 4 (Antibody Development and ELISA) can proceed immediately. Application 2 (Interaction Studies) should be approached with caution and include validation using full-length VacA. For functional VacA studies, consider using full-length protein expressed in appropriate bacterial systems that can support proper autotransporter folding and processing. This systematic approach ensures appropriate use based on protein characterization.
