摘要
Through the method of initial heat release rate, the kinetic property of tyrosine oxidation catalyzed by tyrosinase from Pseudomonas maltophilia was investigated using a LKB-2107 batch microcalorimeter. Tyrosine was catalyzed and oxidized into L-dopa, then into melanin catalyzed by tyrosinase. We found that the tyrosinase reaction obeyed the Michaelis-Menten kinetics, and at 298.15K and pH 7.0, the initial exothermic rate (W0 ) are in the range of 0.1567~0.5704 mJ·s-1, the maximum exothermic rate (Wmax) are in 0.4152 ~ 0.8143mol·L-1, and mean value of the Michaelis constant (Km) is 2.199±0.105104 mol·L-1.
Through the method of initial heat release rate, the kinetic property of tyrosine oxidation catalyzed by tyrosinase from Pseudomonas maltophilia was investigated using a LKB-2107 batch microcalorimeter. Tyrosine was catalyzed and oxidized into L-dopa, then into melanin catalyzed by tyrosinase. We found that the tyrosinase reaction obeyed the Michaelis-Menten kinetics, and at 298.15K and pH 7.0, the initial exothermic rate (W0 ) are in the range of 0.1567~0.5704 mJ·s-1, the maximum exothermic rate (Wmax) are in 0.4152 ~ 0.8143mol·L-1, and mean value of the Michaelis constant (Km) is 2.199±0.105104 mol·L-1.
基金
This work were supported by the National Natural Science Foundation of China(No.30170010,29973030)
The Teaching and Research Award Program for Outstanding Young Professors in High Education Institute,MOE,China(2001).
