Table_4_Investigation of Protein and Epitope Characteristics of Oats and Its Implications for Celiac Disease.XLSX

The use of pure oats (oats cultivated with special care to avoid gluten contamination from wheat, rye, and barley) in the gluten-free diet (GFD) represents important nutritional benefits for the celiac consumer. However, emerging evidence suggests that some oat cultivars may contain wheat gliadin analog polypeptides. Consequently, it is necessary to screen oats in terms of protein and epitope composition to be able to select safe varieties for gluten-free applications. The overall aim of our study is to investigate the variability of oat protein composition directly related to health-related and techno-functional properties. Elements of an oat sample population representing 162 cultivated varieties from 20 countries and the protein composition of resulting samples have been characterized. Size distribution of the total protein extracts has been analyzed by size exclusion-high performance liquid chromatography (SE-HPLC) while the 70% ethanol-extracted proteins were analyzed by RP-HPLC. Protein extracts separated into three main groups of fractions on the SE-HPLC column: polymeric proteins, avenins (both containing three subgroups based on their size), and soluble proteins, representing respectively 68.79–86.60, 8.86–27.72, and 2.89–11.85% of the total protein content. The ratio of polymeric to monomeric proteins varied between 1.37 and 3.73. Seventy-six reversed phase-HPLC-separated peaks have been differentiated from the ethanol extractable proteins of the entire population. Their distribution among the cultivars varied significantly, 6–23 peaks per cultivar. The number of appearances of peaks also showed large variation: one peak has been found in 107 samples, while 15 peaks have been identified, which appeared in less than five cultivars. An estimation method for ranking the avenin-epitope content of the samples has been developed by using MS spectrometric data of collected RP-HPLC peaks and bioinformatics methods. Using ELISA methodology with the R5 antibody, a high number of the investigated samples were found to be contaminated with wheat, barley, or rye.

纯燕麦（指经特殊培育以避免小麦、黑麦和黑麦谷蛋白污染的燕麦）在无麸质饮食（GFD）中的应用，对乳糜泻患者而言具有重要的营养价值。然而，最新的研究证据表明，某些燕麦品种可能含有小麦谷蛋白类多肽。因此，对燕麦进行蛋白质和表位组成的筛查，以选择适合无麸质应用的安全品种，显得尤为必要。本研究的总体目标在于探究与健康相关和工艺功能特性直接相关的燕麦蛋白质组成的变异性。通过对来自20个国家、162个栽培品种的燕麦样本群体进行表征，以及对蛋白质组成进行了分析。总蛋白质提取物的大小分布通过尺寸排阻高效液相色谱（SE-HPLC）进行分析，而70%乙醇提取的蛋白质则通过反相高效液相色谱（RP-HPLC）进行检测。蛋白质提取物在SE-HPLC柱上被分离为三个主要组分：聚合物蛋白、燕麦蛋白（根据其大小分为三个亚组）和可溶性蛋白，分别占总蛋白质含量的68.79%-86.60%、8.86%-27.72%和2.89%-11.85%。聚合物蛋白与单体蛋白的比例介于1.37至3.73之间。从整个群体中可提取的乙醇蛋白中区分出了76个反相-HPLC分离峰，这些峰在不同品种中的分布存在显著差异，每个品种有6-23个峰。峰的出现次数也呈现出较大的变异性：在107个样本中发现了1个峰，而在少于五个品种中识别出了15个峰。通过使用收集到的RP-HPLC峰的质谱数据以及生物信息学方法，开发了一种估算样本燕麦蛋白表位含量的方法。利用ELISA方法与R5抗体，发现大量研究样本受到小麦、黑麦或大麦的污染。