天然抗氧化肽对肠肽酶的耐受性及其跨膜转运机制

项目名称： 天然抗氧化肽对肠肽酶的耐受性及其跨膜转运机制

项目编号： No.31271846

项目类型： 面上项目

立项/批准年度： 2013

项目学科： 农业科学

项目作者： 李博

作者单位： 中国农业大学

项目金额： 78万元

中文摘要： 活性肽潜在的生理功效在于经过口服后能否到达靶器官。小肠上皮细胞吸收屏障及其酶系统是活性肽口服进入机体的关键障碍所在。本研究以抗氧化肽为研究对象，以酪蛋白为原料酶法制备多肽混合物，采用色谱技术分离出高活性组分；采用胃液-肠液- Caco-2 细胞的三段式模型模拟体外连续消化吸收。着重研究抗氧化肽在小肠上皮细胞的代谢和吸收规律；研究分子量、荷电性和疏水性等结构性质与肽的耐消化性及其跨膜转运路径之间的内在联系。通过质谱图比对识别并鉴定完整转运的抗消化肽，研究抗消化肽的结构特征，进一步鉴定高活性抗消化肽。本课题创新地运用"组学"的研究方法，通过组群指标分析，揭示抗氧化肽的降解和跨膜转运机制及其影响因素，阐明口服抗氧化肽的生物可达性以及抗消化肽的结构特征。该研究有助于人们了解生物活性肽以及影响活性肽的生物利用度和吸收的因素，丰富寡肽吸收理论，并为生产具有"真正功效"的抗氧化肽功能食品提供理论依据。

中文关键词： 抗氧化肽；结构性质；Caco-2 单层细胞；跨膜转运；生物利用度

英文摘要： The physiological effects of bioactive peptides depend on their ability to reach their target sites in intact forms after oral intake. The intestinal absorption barrier and the susceptibility to action of enzymes in intestinal epithelium are the key biological barrier for bioactive peptides from oral intake into the blood stream. In this proposal, antioxidative peptides were chosen as a model of bioactive peptides. The casein was hydrolyzed by proteases to obtain antioxidative hydrolysates. Peptides showing strong antioxidant activities were isolated from the hydrolysate using chromatographic methods. A three-stage in vitro model system of simulated gastric juice - intestinal juice and Caco-2 Cell monolayers, was used to simulate the process of human gastrointestinal (GI) digestion and absorption of peptides. The study focuses on the processes governing the digestion, absorption and transport of peptide molecules across the intestinal epithelium. Insight into resistance to intestinal peptidases and transepithelial transport pathways of antioxidative peptides affected by peptide structural parameters, such as molecular masses, charge and electronic properties, hydrophobicity, are studied. The peptides absorbed intact are identified by comparing mass spectrum of peptides before and after transepithelial transport

英文关键词： antioxidant peptide；structural characteristics；Caco-2 monolayer cell；transepithelial transport；bioavailability