Catalytic Triad · Ser195–His57–Asp102
unseel.com · charge-relay · oxyanion hole · ~10⁹ rate boost
Rate boost ~10⁹×
Ser Oγ pKa 13
Step
Ser195 (nucleophile)
His57 (general base)
Asp102 (stabilizer)
Substrate / proton
Unseel.com · Serine Protease Catalytic Triad