Báo cáo khoa học: Electrostatic role of aromatic ring stacking in the pH-sensitive modulation of a chymotrypsin-type serine protease, Achromobacter protease I

Achromobacterprotease I (API) has a unique region of aromatic ring stacking with Trp169–His210in close proxi-mity to the catalytic triad. This paper reveals the electrostatic role of aromatic stacking in the shift in optimum pH to the alkaline region, which is the highest pH range (8.5–10) among chymotrypsin-type serine proteases. The pH-activity profile of API showed a sigmoidal distribution that appears at pH 8–10, with a shoulder at pH 6–8.