Juhász Angéla, Nye-Wood Mitchell G, Tanner Gregory J, Colgrave Michelle L
School of Science, Edith Cowan University, Joondalup, WA, Australia.
School of Biosciences, University of Melbourne, Melbourne, VIC, Australia.
Front Nutr. 2022 Aug 10;9:977206. doi: 10.3389/fnut.2022.977206. eCollection 2022.
Wheat is a major source of nutrition, though in susceptible people it can elicit inappropriate immune responses. Wheat allergy and non-celiac wheat sensitivity are caused by various wheat proteins, including alpha-amylase trypsin inhibitors (ATIs). These proteins, like the gluten proteins which can cause celiac disease, are incompletely digested in the stomach such that immunogenic epitopes reach the lower digestive system where they elicit the undesirable immune response. The only completely effective treatment for these immune reactions is to eliminate the food trigger from the diet, though inadvertent or accidental consumption can still cause debilitating symptoms in susceptible people. One approach used is to prevent the causal proteins from provoking an immune reaction by enhancing their digestion using digestive protease supplements that act in the stomach or intestine, cleaving them to prevent or quench the harmful immune response. In this study, a digestive supplement enriched in caricain, an enzyme naturally present in papaya latex originally designed to act against gluten proteins was assessed for its ability to digest wheat ATIs. The digestion efficiency was quantitatively measured using liquid chromatography-mass spectrometry, including examination of the cleavage sites and the peptide products. The peptide products were measured across a digestion time course under conditions that mimic gastric digestion , involving the use of pepsin uniquely or in combination with the supplement to test for additive effects. The detection of diverse cleavage sites in the caricain supplement-treated samples suggests the presence of several proteolytic enzymes that act synergistically. Caricain showed rapid action against known immunogenic ATIs, indicating its utility for digestion of wheat ATIs in the upper digestive tract.
小麦是主要的营养来源，不过对于易感人群，它会引发不适当的免疫反应。小麦过敏和非乳糜泻性小麦敏感是由多种小麦蛋白引起的，包括α-淀粉酶胰蛋白酶抑制剂（ATIs）。这些蛋白质，就像能导致乳糜泻的麸质蛋白一样，在胃中不能被完全消化，以至于免疫原性表位到达下消化道，在那里引发不良免疫反应。对于这些免疫反应，唯一完全有效的治疗方法是从饮食中消除引发食物，不过不经意或意外食用仍会在易感人群中引起使人虚弱的症状。一种采用的方法是通过使用在胃或肠道中起作用的消化蛋白酶补充剂来增强这些致病蛋白的消化，从而防止它们引发免疫反应，将它们分解以预防或抑制有害的免疫反应。在这项研究中，评估了一种富含木瓜蛋白酶的消化补充剂的能力，木瓜蛋白酶是木瓜乳胶中天然存在的一种酶，最初设计用于对抗麸质蛋白，以消化小麦ATIs。使用液相色谱-质谱法定量测量消化效率，包括检查切割位点和肽产物。在模拟胃消化的条件下，在整个消化时间过程中测量肽产物，单独使用胃蛋白酶或与补充剂联合使用以测试相加效应。在木瓜蛋白酶补充剂处理的样品中检测到不同的切割位点，表明存在几种协同作用的蛋白水解酶。木瓜蛋白酶对已知的免疫原性ATIs显示出快速作用，表明其在上消化道消化小麦ATIs方面的效用。
