Abstract:
Human milk reduces risk for necrotizing enterocolitis in preterm infants. Necrotizing enterocolitis occurs in the ileocecal region where thousands of milk protein-derived peptides have been released from digestion. Digestion-released peptides may exert bioactivity, such as antimicrobial and immunomodulatory activities, in the gut. In this study, we applied mass spectrometry-based peptidomics to characterize peptides present in colostrum before and after in vitro digestion. Sequence-based computational modeling was applied to predict peptides with antimicrobial activity. We identified more peptides in undigested samples, yet the abundances were much higher in the digested samples. Heatmapping demonstrated highly different peptide profiles between undigested and digested samples. Four peptides (αS1-casein [157-163], αS1-casein [157-165], β-casein [153-159] and plasminogen [591-597]) were selected, synthesized and tested against common pathogenic bacteria associated with necrotizing enterocolitis. All four exhibited bacteriostatic, though not bactericidal, activities against Klebsiella aerogenes, Citrobacter freundii and Serratia marcescens, but not Escherichia coli.
摘要:
母乳可降低早产儿坏死性小肠结肠炎的风险。坏死性小肠结肠炎发生在回盲区,在那里成千上万的乳蛋白衍生肽已从消化中释放出来。消化释放肽可以发挥生物活性,如抗菌和免疫调节活性,在肠子里.在这项研究中,我们应用基于质谱的肽组学来表征体外消化前后初乳中存在的肽。基于序列的计算模型用于预测具有抗微生物活性的肽。我们在未消化的样品中发现了更多的肽,然而,消化样品中的丰度要高得多。Heatmapping显示了未消化和消化样品之间高度不同的肽谱。四种肽(αS1-酪蛋白[157-163],αS1-酪蛋白[157-165],选择β-酪蛋白[153-159]和纤溶酶原[591-597]),合成并测试了与坏死性小肠结肠炎相关的常见致病菌。所有四个都表现出抑菌,虽然不是杀菌,针对产气克雷伯菌的活动,弗氏柠檬酸杆菌和粘质沙雷菌,但不是大肠杆菌。