International Journal of Food Properties   2016 年 19 卷 11 期

2016.11.01

Gallic acid is one of the important polyphenols in plants and it inhibits ?±-amylase. The interaction between gallic acid and ?±-amylase was investigated by fluorescence quenching spectroscopy, UV-vis spectroscopy, synchronous spectroscopy, and the three-dimensional fluorescence spectroscopy under mimic physiological conditions. The result of the emission quenching at different temperatures revealed that there are static quenching of intrinsic fluorescence of ?±-amylase induced by gallic acid and a complex of gallic acid-?±-amylase was formed. The results obtained from the evaluation of three-dimensional fluorescence spectra, UV-vis spectra, and synchronous spectra suggested that the association between gallic acid and ?±-amylase did change the molecular conformation of ?±-amylase. Gallic acid can enter the primary substrate-binding pocket and alter the microenvironment around tryptophan and tyrosine residues.