Anti-CRASP-2

CRASP-2 (Complement Regulator-Acquiring Surface Protein 2) of Borrelia burgdorferi binds FHL-1 and factor H binding protein in a distinct way. It may be predominantly expressed by serum-resistant Borrelia strains. Borrelia burgdorferi sensu lato has the ability to evade immune systems to persist in a variety of vertebrate hosts. This activity is dependent on a number of factors. Some Borrelia species bind host-derived fluid-phase immune regulators FHL-1 and factor H to their surface via complement regulator-acquiring surface proteins (CRASPs). Factor H and FHL-1 serve as cofactors for factor I, a serine protease that cleaves complement component 3b (C3b) directly on the cell surface and thereby confers resistance of spirochetes to complement-mediated lysis. It is possible that because of discontinuous binding regions in the factor H/FHL-1, long distance interaction may be involved in binding of both immune regulators. Putative coiled-coil structural elements may be important in the interaction of B. burgdorferi CRASP-1 with factor H.