Inhibition of α-amylase activity by cellulose: Kinetic analysis and nutritional implications
Inhibition of α-amylase activity by cellulose: Kinetic analysis and nutritional implications
复制标题
DOI：
10.1016/j.carbpol.2015.01.039
复制
发表时间：
2015-06-05
影响因子：
11.2
通讯作者：
Warren, Frederick J.
中科院分区：
文献类型：
--
作者：
Dhital, Sushil;Gidley, Michael J.;Warren, Frederick J.
本文报道了纤维素对α -淀粉酶活性的抑制作用。水解介质中纤维素的存在以浓度依赖的方式降低了淀粉水解的初始速度。α -淀粉酶对纤维素的吸附是可逆的，在30分钟内达到平衡，并且在37℃下比在20℃和0℃下表现出更高的亲和力。在麦芽糖（2.5-20 mM）的存在下，吸附几乎没有变化，但在过量蛋白质的存在下，吸附受到阻碍，表明α -淀粉酶对纤维素的非特异性吸附。对纤维素存在下玉米淀粉α -淀粉酶水解的动力学分析表明，这种抑制是混合型的。El配合物的解离常数（K-ic）约为3 mg/mL。对α -淀粉酶活性的抑制表明，饲粮中的纤维素可能会减弱淀粉的水解。(C) 2015 Elsevier Ltd.版权所有。
We report on inhibition of alpha-amylase activity by cellulose based on in vitro experiments. The presence of cellulose in the hydrolysing medium reduced the initial velocity of starch hydrolysis in a concentration dependent manner. alpha-Amylase adsorption to cellulose was reversible, attaining equilibrium within 30 min of incubation, and showed a higher affinity at 37 degrees C compared to 20 and 0 degrees C. The adsorption was almost unchanged in the presence of maltose (2.5-20 mM) but was hindered in the presence of excess protein, suggesting non-specific adsorption of alpha-amylase to cellulose. Kinetic analyses of alpha-amylase hydrolysis of maize starch in the presence of cellulose showed that the inhibition is of a mixed type. The dissociation constant (K-ic) of the El complex was found to be ca. 3 mg/mL. The observed inhibition of alpha-amylase activity suggests that cellulose in the diet can potentially attenuate starch hydrolysis. (C) 2015 Elsevier Ltd. All rights reserved.