Streptopain
Streptopain, also known as streptococcal pyrogenic exotoxin B is a streptococcal cysteine protease. Other names include Streptococcus peptidase A, Streptococcus protease, and streptococcal cysteine proteinase. Streptopain catalyses the following chemical reaction
It is isolated from the group A bacterium Streptococcus pyogenes and acts as a virulence factor.