This virulence factor of S.pyogenes specifically cleaves the human serum chemotaxin C5a at '68-Lys-|-Asp-69' bond near its C-terminus, destroying its ability to serve as a chemoattractant. The primary cleavage site is at 67-His-|-Lys-68 in human C5a with a minor secondary cleavage site at 58-Ala-|-Ser-59. Belongs to the peptidase S8 family.