Identification of food-derived peptide and its bioactivities after oral ingestion of hydrolysate prepared from connective tissues

在目前的研究中，我们确定Pro-甘氨酸(Pro-Gly)是口服弹性蛋白水解物后人体血液中的食源性多肽。健康志愿者摄入弹性蛋白水解物(10g/60 kg体重)后，取外周血制备血浆样品，用固相萃取法提取多肽，并用体积排阻色谱(SEC)进行分级。SEC组分中的多肽用异硫氰酸苯酯(PITC)衍生化，并用反相(RP)-高效液相色谱法进行拆分。Pro-Gly是主要的食源性弹性蛋白多肽，在摄入后30分钟达到最大值(18μM)，并在摄入后4小时下降约20%。在细胞培养中，1μg/mL以上浓度的Pro-Gly可显著促进正常人真皮成纤维细胞弹性蛋白的合成，而不影响细胞的增殖率。

In the present study, we identified prolyl-glycine (Pro-Gly) as the food-derived peptide in human blood after oral ingestion of elastin hydrolysate. Following ingestion of elastin hydrolysate (10 g/60 kg body weight) by healthy human volunteers, peripheral blood was used to prepare plasma samples from which peptides were extracted by solid phase extraction and fractionated by size-exclusion chromatography (SEC). Peptides in the SEC fractions were derivatized with phenyl isothiocyanate (PITC) and resolved by reverse phase (RP)-HPLC. Pro-Gly was the major food-derived elastin peptide, reaching a maximum (18 μM) at 30 minutes after ingestion, and decreasing approximately20% at 4 hours after ingestion. Finally, in cell culture, levels of Pro-Gly in the medium above 1 μg/mL significantly enhanced elastin synthesis of normal human dermal fibroblasts (NHDF) without affecting the rate of cell proliferation.