Recombinant E.coli isaB protein

**Background of IsaB Recombinant Protein**

IsaB (immunodominant staphylococcal antigen B) is a cell wall-associated protein originally identified in *Staphylococcus aureus*, a major bacterial pathogen responsible for diverse infections, ranging from skin abscesses to life-threatening sepsis. The *isaB* gene is part of the *isaA* (immunodominant staphylococcal antigen A) operon, which is regulated by the *sigB* stress-response sigma factor. IsaB is expressed during bacterial stress conditions, such as nutrient limitation or host immune challenges, suggesting a role in *S. aureus* adaptation and survival within hostile environments.

Studies indicate that IsaB contributes to immune evasion by interacting with host components. It exhibits structural similarities to other staphylococcal surface proteins involved in adhesion, biofilm formation, or modulation of host defenses. While its precise mechanistic role remains under investigation, IsaB has been implicated in reducing bacterial susceptibility to phagocytosis, potentially by masking pathogen-associated molecular patterns (PAMPs) or interfering with opsonization.

Recombinant IsaB protein is produced via heterologous expression systems (e.g., *E. coli*) for research and therapeutic applications. Its production enables the study of *S. aureus* pathogenesis, host-pathogen interactions, and immune responses. Recombinant IsaB is also explored as a diagnostic antigen or vaccine candidate due to its immunogenicity. Antibodies against IsaB have been detected in patients with *S. aureus* infections, highlighting its relevance as a target for immune-based strategies.

Overall, IsaB recombinant protein serves as a critical tool for understanding staphylococcal virulence and advancing novel antimicrobial interventions.