The effects of tea polyphenols on binding of porcine pancreatic α-amylase (PPA) with normal maize starch granules were studied through solution depletion assays, fluorescence spectroscopy and initial rate kinetics. Only polyphenols which have inhibitory activity against PPA increased the binding of PPA with starch. The results are consistent with a binding equilibrium between polyphenols, starch and PPA. The dissociation constant (K_d) for PPA binding was decreased by tea polyphenols, with the effects greater for theaflavins than catechins and for galloylated than non-galloylated polyphenols. Tea polyphenols were also shown to increase the binding rate of PPA to starch. In addition, there were positive linear correlations between 1/K_d and reciprocal of competitive inhibition constant (1/K_ic) and between 1/K_d and fluorescence quenching constant (K_FQ). Despite the greater amount of PPA on the granules, starch hydrolysis is reduced because the polyphenol inhibition of PPA persists after binding to starch.

通过溶液耗竭试验，荧光光谱和初始速率动力学研究茶多酚对猪胰腺α-淀粉酶（PPA）与正常玉米淀粉颗粒结合的影响。只有对PPA具有抑制活性的多酚才能提高PPA与淀粉的结合力。结果与多酚，淀粉和PPA之间的结合平衡相符。茶多酚降低了PPA结合的解离常数（K _d），其茶黄素的活性高于儿茶素，而没食子酸酯的多酚的作用大于未酚基的多酚。茶多酚还显示出增加PPA与淀粉的结合率。此外，1 / K _d之间存在正线性相关竞争抑制常数（1 / K _ic）和1 / K _d与荧光猝灭常数（K _FQ）之间的倒数。尽管颗粒上的PPA含量较大，但由于PPA与淀粉结合后对多酚的抑制作用仍然存在，因此淀粉的水解减少了。