The invention relates to an isolated immunoglobulin heavy chain polypeptide and an isolated immunoglobulin light chain polypeptide that binds to complement protein C5. The invention provides a C5-binding agent that comprises the aforementioned immunoglobulin heavy chain polypeptide and immunoglobulin light chain polypeptide. The invention provides an isolated complement protein C5 epitope. The invention also provides related vectors, compositions, and methods of using the C5-binding agent to treat an C5-mediated disease.
