The disclosure provides peptide compounds that regulate the complement systemand methods of using these compounds.Specificall the disclosure provides an isolated, purified peptide of 30 aminoacids derived from human astrovirus protein,called CP1. The peptide compounds disclosed include peptide mimetics, peptideanalogs and/or synthetic derivatives of CP1 having,for example, internal peptide deletions and/or substitutions, deletions and/orsubstitutions at the N-terminus and C-terminus,and that are able to regulate complement activation. The disclosure furtherprovides pharmaceutical compositions comprising therapeuticallyeffective amounts of the peptide compounds and a pharmaceutically acceptablecarrier, diluent, or excipient for treatinga disease or condition associated with complement-mediated tissue damage.
