Competitive and product inhibition-based α-amylase activity analysis method

Objectives To propose a methodology for analyzing salivary α-amylase activity (sAMY) for a hand-held device that can be used easily and quickly for evaluating human psychological effects. Methods An improved method for the analysis of sAMY is proposed using competitive and product inhibition in a dry-chemistry system with a reagent paper containing 2-chloro-4-nitrophenyl-4-O-β-d-galactopyranosylmaltoside. Results Not only the competitive (maltopentaose) inhibitor, but also the product (maltotriose) inhibitor significantly reduce the reaction speed of sAMY. There is an independent effect between the two inhibitors. The dynamic linear range of the analysis can be enhanced by 2.5 times larger by adding the competitive and product inhibitors simultaneously and by preparing their concentrations appropriately. Conclusions It is considered that the application of competitive and product inhibition can be effective from the viewpoint of enhancing analysis range and effectively reducing costs.