Abstract:Alpha-glucosidase inhibitors can inhibit carbohydrate hydrolysis and are commonly used to decrease postprandial blood glucose in individuals with hyperglycemia. A model for the rapid screening of trace amounts of alpha-glucosidase inhibitors was established based on the alpha-glucosidase-pNPG in vitro reaction system. The optimized parameters of this model were as follows: the enzyme concentration, substrate concentration, reaction temperature, and reaction time were 0.05 U/mL, 0.05~1 mM, 37 ℃, and 6 min, respectively. The inhibitory effect of acarbose was determined using this model, and the enzymatic reaction kinetics data were analyzed using five methods (Lineweaver-Burk plots, Eadie-Hofstee plots, Hanes-Wolff plots, Eisenthal-Cornish-Bowden direct plots, and Non-linear regression analysis). Data processing and comparison of results showed that these five methods had distinct characteristics as the Ki, Km, and Vmax calculated by these five methods differed slightly. Non-linear Regression Analysis was more convenient, reasonable, and reliable, and therefore was the first choice for processing the data of enzyme kinetics. By this model, the Vmax (?10-6 mmol/min) and Km (mM) of enzymatic reaction were calculated to be 3.91 and 0.12, respectively and the Ki (μM) of acarbose was 90.
