摘要
目的探讨β-伴大豆球蛋白(β-conglycinin,7S)和大豆球蛋白(glycinin,11S)对猪胰α-淀粉酶(porcine pancreaticα-amylase,PPA)的抑制动力学特征。方法通过测定半抑制浓度(halfmaximalinhibitory concentration,IC_(50)),结合Cornish-Bowden方程和Dixon方程,对7S和11S对PPA的抑制类型及抑制作用进行阐述。结果7S对PPA的抑制作用属于混合型竞争性抑制,而11S对PPA抑制作用主要是竞争性抑制。7S和11S的竞争性抑制常数(competitive inhibition constants,Kic)分别为3.958 mg/mL和37.083 mg/mL,7S的反竞争性抑制常数(uncompetitive inhibition constants,K_(iu))为37.394 mg/mL。7S的IC_(50)值为49.771 mg/mL。7S的Kic比K_(iu)小,这说明7S与游离的猪胰α-淀粉酶结合更密切,而与淀粉和PPA形成的中间产物结合较为疏松。结论7S和11S均通过抑制淀粉酶的活性来达到延缓淀粉类食品消化的目的,而且7S对猪胰α-淀粉酶抑制作用更强。
Objective To investigate the inhibitory kinetic characteristics of porcine pancreaticα-amylase(PPA)byβ-conglycinin(7 S)and glycinin(11 S).Methods The inhibitory types and effects of 7 S and 11 S on PPA were described by measuring the half maximal inhibitory concentration(IC_(50))and combining with Cornish-Bowden equation and Dixon equation.Results The inhibitory effect of 7 S on PPA belonged to mixed competitive inhibition,while the inhibitory effect of 11 S on PPA was mainly competitive inhibition.The competitive inhibition constants(Kic)of 7 S and 11 S were 3.958 mg/mL and 37.083 mg/mL,respectively,and the uncompetitive inhibition constants(K_(iu))of 7 S was 37.394 mg/mL.The IC_(50) value of 7 S was 49.771 mg/mL.The Kic of 7 S was smaller than that of K_(iu),which indicated that 7 S bound more closely to free porcine pancreaticα-amylase,but loosely bound to the intermediates formed by starch and PPA.Conclusion Both 7 S and 11 S achieve the purpose of delaying the digestion of starchy foods by inhibiting the activity of amylase,and 7 S has a stronger inhibitory effect on porcine pancreaticα-amylase.
作者
罗明昌
张昱格
朱宝燕
张福荣
陈旭
LUO Ming-Chang;ZHANG Yu-Ge;ZHU Bao-Yan;ZHANG Fu-Rong;CHEN Xu(Dongguan Dongmei Food Co.,Ltd.,Dongguan 523279,China;Key Laboratory of Healthy Food Development and Nutrition Regulation of China National Light Industry,Engineering Research Center of Health Food Design&Nutrition Regulation,School of Chemical Engineering and Energy Technology,Dongguan University of Technology,Dongguan 523808,China)
出处
《食品安全质量检测学报》
CAS
北大核心
2022年第2期536-543,共8页
Journal of Food Safety and Quality
基金
广东省自然科学基金面上项目(2020A1515011341)
东莞理工学院高层次人才(创新团队)科研启动项目(KCYCXPT2017007)
广东省创新强校工程创新团队项目(2021KCXTD035)
2021年东莞市社会科技发展重点项目(20211800904672)。