Istituto di Scienze dell'Alimentazione-CNR, Via Roma 52 A/C, I-83100 Avellino, Italy.
J Chromatogr B Analyt Technol Biomed Life Sci. 2010 Feb 1;878(3-4):295-308. doi: 10.1016/j.jchromb.2009.11.033. Epub 2009 Nov 20.
Resistance to proteases throughout the gastrointestinal (GI) tract is a prerequisite for milk-derived peptides to exert biological activities. In this work an in vitro multi-step static model to simulate complete digestion of the bovine milk proteins has been developed. The experimental set-up involved the sequential use of: (i) pepsin, (ii) pancreatic proteases, and (iii) extracts of human intestinal brush border membranes, in simulated gastric, duodenal and jejuneal environments, respectively. Enzymatic concentrations and reaction times were selected in order to closely reproduce the in vivo conditions. The aim was to identify the peptide candidates able to exhibit significant bioactive effects. Casein and whey protein peptides which survived the in vitro GI digestion have been identified by the combined application of HPLC and mass spectrometry techniques. While the permanence of the main potentially bioactive peptides from both casein and whey proteins was found of limited physiological relevance, the high resistance to proteolysis of specific regions of beta-lactoglobulin (beta-Lg), and especially that of the peptide beta-Lg f125-135, could have implications for the immunogenic action of beta-Lg in the insurgence of cow's milk allergy.
在胃肠道（GI）中抵抗蛋白酶是乳源肽发挥生物活性的前提条件。在这项工作中，开发了一种体外多步静态模型来模拟牛乳制品的完全消化。实验装置包括顺序使用：（i）胃蛋白酶，（ii）胰蛋白酶，和（iii）人肠刷状缘膜提取物，分别在模拟的胃，十二指肠和空肠环境中。选择了酶浓度和反应时间，以紧密复制体内条件。目的是确定能够表现出显著生物活性的肽候选物。通过高效液相色谱和质谱技术的联合应用，鉴定了在体外 GI 消化中存活的酪蛋白和乳清蛋白肽。虽然酪蛋白和乳清蛋白中主要潜在生物活性肽的持久性具有有限的生理相关性，但β-乳球蛋白（β-Lg）的特定区域和β-Lg f125-135 肽的高抗蛋白酶水解性可能对β-Lg 在牛奶过敏的发生中的免疫作用具有影响。
