鳕鱼源金属螯合肽体外模拟胃肠消化稳定性研究

为了评价鳕鱼皮胶原蛋白源金属螯合肽，Ala-Gly-Pro-Ala-Gly-Pro-Arg(多肽M)，的胃肠消化耐受性，建立体外模拟胃肠消化模型(SGID)，该模型包括模拟人体中胃消化环境和肠消化环境两个阶段。多肽M的钙螯合率为0.88±0.02 μg/mg，铁螯合率为33.67%。胃消化产物S，钙螯合率为0.87±0.03 μg/mg，与纯肽相比钙螯合率下降1.14%；铁螯合率为33.72%，与纯肽相比反而上升0.05%。肠消化产物D，钙螯合率为0.85±0.01 μg/mg，与纯肽相比下降3.40%；铁螯合率为34.13%，与纯肽相比上升0.46%。利用反相高效液相色谱、质谱和圆二色谱技术，发现经过两个阶段多肽M分子量未发生变化，肽键未发生断裂，构象发生变化，其中无规卷曲减少，β折叠和β转角构象增加。因此，多肽M在体外模拟胃肠消化过程中其多肽链氨基酸组成不变，空间构象发生改变，钙铁离子螯合能力变化不大，体外模拟胃肠消化耐受性高。
In order to evaluate the gastrointestinal tolerance of a new Alaska pollock skin collagen-derived metal chelating peptide (Ala-Gly-Pro-Ala-Gly-Pro-Arg, peptide M), an in vitro simulated gastrointestinal digestion (SGID) model was established, and this model included two stages: simulated human gastric digestion and simulated human intestinal digestion. The calcium-chelating activity of peptide M was 0.88 ± 0.02 μg/mg, and its iron-chelating activity was 33.67%. The calcium-chelating activity of gastric digestion product S was 0.87 ± 0.03 μg/mg, a 1.14% decrease compared to the pure peptide. The iron-chelating activity of S was 33.72%, an increase of 0.05% compared to the pure peptide. The calcium-chelating activity of intestinal digestion product D was 0.85 ± 0.01 μg/mg, a 3.40% decrease compared to the pure peptide. And the iron-chelating activity of D was 34.13%, an increase of 0.46% compared to the pure peptide. Reversed-phase high-performance liquid chromatography, full scan mass spectrometry, and circular dichroism showed that after two-stage SGID, M molecule did not show a change in molecular mass or cleavage of peptide bonds, but there were changes in the conformation, including a decrease in the proportion of random coils and increases in the proportions of β-sheets and β-turns. Therefore, during the SGID, the amino acid composition in the peptide was not changed, and the spatial conformation was changed. The calcium- and iron-chelating capabilities were not significantly changed. Peptide M showed a high gastrointestinal tolerance in SGID.