UspA2 protein (UspA2)

UspA2 protein is a large, coiled-coil, trimeric autotransporter adhesin (~62 kDa monomer, forms high-molecular-weight oligomers)[4] presented on the surface of nearly all clinical isolates of *M. catarrhalis*[1][4][5]. UspA2 confers resistance to complement-mediated killing by binding human serum proteins such as vitronectin, C4b-binding protein, factor H, and plasminogen, thereby preventing membrane attack complex (MAC) formation and promoting survival in the human host[1][5]. It also contributes to bacterial adhesion to host cells via host receptor and ECM protein (vitronectin and integrins) binding[3]. UspA2 is immunogenic and a target for vaccine development; its exposed domains are recognized by biologically active antibodies[1][2][3][4][5]. Genetic exchange and recombination within the UspA family (including UspA1, UspA2, and hybrid forms) drive antigenic diversity and may influence functional properties related to adhesion and immune evasion[2][3].

Other names

UspA2 adhesinUspA2 surface proteinUniversal stress protein A2

Experimental drugs/fusion proteins block complement evasion by binding UspA2 to enhance complement-mediated bacterial killing