Bacillus anthracis S-layer protein BslA binds to extracellular matrix by interacting with laminin.

BACKGROUND

The Bacillus anthracis S-layer protein, BslA, plays a crucial role in mammalian infection. BslA is required to mediate adherence between host cells and vegetative forms of bacteria and this interaction promotes target organs adherence and blood-brain barrier (BBB) penetration in vivo. This study attempts to identify the potential eukaryotic ligand(s) for B. anthracis BslA protein.

RESULTS

Biochemical approaches have indicated that the putative host cell ligand(s) for BslA is a surface protein, which is independent of the sugar components for binding to Bs1A. A ligand screening using blot overlays, far Western blots and mass spectrometry analyses revealed that BslA binds to mammalian laminin. ELISA based solid-phase binding assays and surface plasmon resonance assays demonstrated that there were high affinity interactions between BslA(260-652) and laminin. The SPR results also revealed the dissociation constants values of 3.172 × 10(-9)M for the binding of BslA(260-652) to laminin.

CONCLUSIONS

These data demonstrated that laminin is a ligand for BslA.