fbpA/Ag85A Recombinant Rabbit mAb (S-3736-20)

The fbpA/Ag85A protein (fibronectin-binding protein A, also known as antigen 85A) is a critical virulence factor and major protective antigen secreted by Mycobacterium tuberculosis, representing the most immunogenic component of the Ag85 complex (which comprises Ag85A, B, and C); this protein possesses a unique dual-functional domain structure, where its N-terminus exhibits fibronectin-binding activity that mediates bacterial adhesion to the host extracellular matrix to facilitate invasion and colonization, while its C-terminus displays potent mycolyltransferase activity responsible for catalyzing the transfer of mycolic acids from trehalose monomycolate to arabinogalactan or another trehalose monomycolate molecule—a process essential for constructing the thick, hydrophobic cell wall characteristic of mycobacteria. Furthermore, due to its ability to strongly stimulate host Th1-type immune responses and induce protective antibodies, Ag85A has become a core target for the development of various tuberculosis subunit vaccine candidates and diagnostic reagents.