Activation and Stabilization of Mushroom Tyrosinase by Addition of Polyethylene Glycols pp. 311-322
Authors: (Zhen Yang, Ya-Jun Yue, Ting-Wei Chen, College of Life Sciences, Shenzhen University, Shenzhen, China)
Abstract: Effect of polyethylene glycol (PEG) and its molecular weight on the activity and stability of mushroom tyrosinase was studied systematically. The kinetic parameters (such as Km, Vmax, optimal pH and temperature, and activation energy) and the thermostability of the enzyme at different temperatures were determined and compared in the aqueous solution with and without addition of PEGs. Polyethylene glycol showed the ability of both activating and stabilizing the enzyme (e.g., a 1.6-fold increase in Vmax/Km and a 1.8-fold increase in t1/2 were achieved in the presence of PEG 10000), and such PEG-induced activation and stabilization effect was molecular weight dependent. Both our activity and stability data suggest that PEG can affect the enzyme activity and stability basically via its interaction with the enzyme so as to modify the enzyme‘s active site and conformation or steric structure.