Characterization, activity detection, and overexpression of plant myrosinases
學生姓名:
許芷菱
指導教授:
林泓廷
學期:
111上
摘 要:
Myrosinases (EC 3.2.1.147) are enzymes known for the hydrolysis of glucosinolates, a group of secondary metabolites occurring in all the vegetables belonging to the Brassicaceae family. The reaction mechanisms of myrosinases are widely studied, in order to improve and optimize secondary metabolite production processes. In first study, the myrosinase extracted from white mustard (Sinapis alba) was tested by using a direct UV assay. Then, a new HPLC-UV assay was mentioned to evaluate the activities and kinetics of the myrosinases extracted from broccoli and cauliflower inflorescence, using sinigrin and glucoraphanin as substrates. This method was considered appropriate for the determination of a high myrosinase activity sample and the extrapolation of kinetic parameters without preventive purification. In second study, kinetic and biochemical properties of the broccoli myrosinase enzyme produced from its cDNA cloned in Escherichia coli and Saccharomyces cerevisiae were detected by UV assay. The results revealed that the enzymatic activity of both were best at the optimum value pH 3 and 30℃ . The catalytic efficiency was 4-fold higher in the myrosinases produced in S. cerevisiae than those produced in E. coli. These results will show that a potential application to produce large amounts of myrosinases. Moreover, the hydrolysis products of myrosinase, isothiocyanates, are important for human healthy. It probably allow the development of strategies for the production of bioactive metabolites with potential medical uses.
專題討論20221026_許芷菱-摘要.pdf