Nutrition Program, School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, 2520 SW Campus Way, Corvallis, OR 97331, USA.
Nutrition Program, School of Biological and Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, 2520 SW Campus Way, Corvallis, OR 97331, USA; Department of Food Science and Technology, Oregon State University, 100 Wiegand Hall, Corvallis, OR 97331, USA.
Food Chem. 2023 Jan 1;398:133864. doi: 10.1016/j.foodchem.2022.133864. Epub 2022 Aug 8.
The ability of bovine κ-casein-derived caseinomacropeptide (CMP) to exert bioactivity in the human gut depends on its digestive survival. Sampling from the human jejunum after feeding CMP and top-down glycopeptidomics analysis facilitates the determination of CMP survival. To reduce interference from non-target molecules in mass spectrometric analysis, CMP must be isolated from digestive fluid. To identify an optimal extraction method, this study compared the profiles of CMP extracted from feeding material (commercial CMP in water) and digestive fluid by ethanol precipitation, perchloric acid (PCA) precipitation, and ultrafiltration. Ethanol precipitation yielded the highest ion abundances for aglycosylated CMP and glycosylated CMP in both feeding material and jejunal samples. Notably, PCA precipitation yielded the highest abundance of partially digested CMP-derived fragments in jejunal samples. Overall, ethanol precipitation was the most effective among the methods tested for intact CMP extraction from jejunal fluids, whereas PCA precipitation was optimal for extraction of CMP fragments.
牛κ-酪蛋白衍生的酪蛋白巨肽（CMP）在人体肠道中发挥生物活性的能力取决于其消化后的存活情况。在喂食 CMP 后从人体空肠中取样，并进行自上而下的糖肽组学分析，有助于确定 CMP 的存活情况。为了减少质谱分析中来自非靶向分子的干扰，CMP 必须从消化液中分离出来。为了确定最佳的提取方法，本研究比较了乙醇沉淀、高氯酸（PCA）沉淀和超滤法从喂食材料（水中的商业 CMP）和消化液中提取 CMP 的图谱。乙醇沉淀在喂食材料和空肠样本中均产生了最高的糖苷化 CMP 和糖基化 CMP 的离子丰度。值得注意的是，PCA 沉淀在空肠样本中产生了最多的部分消化的 CMP 衍生片段。总的来说，在测试的从空肠液中提取完整 CMP 的方法中，乙醇沉淀是最有效的，而 PCA 沉淀是提取 CMP 片段的最佳方法。
