College of Food Science and Engineering, South China University of Technology , 381 Wushan Road, Tianhe District, Guangzhou, 510640, China.
Guangdong Province Key Laboratory for Green Processing of Natural Products and Product Safety , 381 Wushan Road, Guangzhou 510640, China.
J Agric Food Chem. 2017 Jul 19;65(28):5778-5788. doi: 10.1021/acs.jafc.7b01951. Epub 2017 Jul 7.
This work reports the influence of glyoxal (GO)-derived glycation on the gastrointestinal enzymatic hydrolysis of β-lactoglobulin and β-casein. Reduced digestibility of glycated proteins was found in both gastric and intestinal stage. Distribution of Maillard reaction products in digests with different molecular weight ranges was investigated subsequently. The colorless and brown MRPs largely presented in the digests smaller than 20 kDa. However, the resistance of fluorescent advanced glycation end products (AGEs) to enzymatic hydrolysis gradually increased during glycation, rendering fluorescent AGEs largely present in the digests larger than 20 kDa. No free N (ε)-carboxymethyllysine (CML) was detected in digests. The relative amount of CML in digests larger than 1 kDa was higher than that of Lys, demonstrating the hindrance of CML to enzymatic hydrolysis. This study highlights the resistance of GO-derived AGEs to digestive proteases via blockage of tryptic cleavage sites or steric hindrance, which is a barrier to the absorption of dietary AGEs.
这项工作报道了乙二醛（GO）衍生的糖化对β-乳球蛋白和β-酪蛋白的胃肠道酶解的影响。在胃和肠阶段都发现糖化蛋白的消化率降低。随后研究了不同分子量范围内消化物中糖基化反应产物的分布。无色和棕色的 MRPs 主要存在于小于 20 kDa 的消化物中。然而，荧光性晚期糖基化终产物（AGEs）对酶水解的抵抗力在糖化过程中逐渐增加，导致荧光 AGEs 主要存在于大于 20 kDa 的消化物中。在消化物中未检测到游离 N（ε）-羧甲基赖氨酸（CML）。大于 1 kDa 的消化物中 CML 的相对含量高于 Lys，表明 CML 对酶水解有阻碍作用。这项研究强调了 GO 衍生的 AGEs 通过阻止胰蛋白酶切割位点或空间位阻来抵抗消化蛋白酶，这是膳食 AGEs 吸收的障碍。
