以兒茶酚為基質，草蝦兩種多酚氧化酶異構酶F1及F2均表現出自殺型動力學反應(suicide kinetics)，酵素失活時間與兒茶酚濃度有關，其動力學機制屬於多基質機制(multisubstrate mechanism)。根據Canovas等人之公式可求得自殺反應常數X，而以1/X v.s. 1/s倒數作圖可得最大自殺反應速率X max以及達到1/2X max之兒茶酚濃度Ks, F1與F2之X max各為6.9與3.4min-1，而兩者之Ks分別為0.078與0.127mM。 Both polyphenol oxidase isozymes Fl and F2 obtained from grass shrimp exhibited suicide kinetics when with catechol was used as substrate. The kinetic analysis suggested that the inactivation of both Fl and F2 were consistent with multisubstrates uicide mechanism. The suicide inactivation rate increased as the catechol concentration increased. The suicide inactivation rate constant λ was determined according to Canovas et al. The maxium suicide inactivation rate Constants of Fl and F2 were 6.9 and 3.4 min-1, respectively. The catechol concentrations for halfmaximal inactivation of Fl and F2 were determined as O.078 mM and O.127 mM, respectively.