A group of toxins produced by Streptococcus pyogenes and responsible for many of the pathological sequelae of infection. Several (SPEA, SPEC, SPEX) are superantigens. SPEB is a cysteine peptidase (streptopain: peptidase 22.214.171.124, 398 aa) which possesses mitogenic activity but, when pure, is not a superantigen. SPEA (streptococcal pyrogenic exotoxin A) is a phage-encoded exotoxin. SPEA and SPEC show strong sequence homology to the staphylococcal enterotoxins.
Subjects: Medicine and Health.