State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, PR China.
State Key Laboratory of Food Science and Technology, Jiangnan University, Wuxi, PR China; School of Food Science and Technology, Jiangnan University, Wuxi, PR China.
Food Chem. 2021 Jun 15;347:129062. doi: 10.1016/j.foodchem.2021.129062. Epub 2021 Jan 12.
Walnut protein was hydrolyzed with different proteases to evaluate the hydrolytic efficiency and dipeptidyl peptidase IV (DPP-IV) inhibitory activity in vitro. All of walnut protein hydrolysates (WPHs) exhibited DPP-IV inhibitory activity and Alcalase-derived hydrolysate (WPH-Alc) with better DPP-IV inhibitory activity of 33.90% (at 0.50 mg/mL) was subsequently separated by ultrafiltration and cation exchange chromatography on a SP Sephadex C-25 column. The results showed that fractions with lower molecular weight and higher basic amino acid residues possessed stronger DPP-IV inhibitory activity. Comparably, the obtained fraction B with the yield of 19.80% had the highest DPP-IV inhibitory activity of 76.19% at 0.25 mg/mL. Moreover, nine novel DPP-IV inhibitory peptides were identified using MALDI-TOF/TOF-MS. Molecular docking revealed the peptides could interact with DPP-IV through hydrogen bonds, salt bridges, hydrophobic interactions, π-cation bonds and π-π bonds. The walnut DPP-IV inhibitory peptides showed better stability with heating treatment, pH treatment, or in vitro gastrointestinal digestion.
采用不同蛋白酶水解山核桃蛋白，评价其体外酶解效率和二肽基肽酶 IV（DPP-IV）抑制活性。所有山核桃蛋白水解物（WPHs）均表现出 DPP-IV 抑制活性，其中碱性蛋白酶（Alcalase）衍生的水解物（WPH-Alc）的 DPP-IV 抑制活性最好，为 33.90%（在 0.50mg/mL 时），随后通过超滤和阳离子交换色谱 SP Sephadex C-25 柱进行分离。结果表明，具有较低分子量和较高碱性氨基酸残基的级分具有更强的 DPP-IV 抑制活性。相比之下，收率为 19.80%的获得级分 B 具有最高的 DPP-IV 抑制活性，为 76.19%（在 0.25mg/mL 时）。此外，使用 MALDI-TOF/TOF-MS 鉴定了 9 种新型 DPP-IV 抑制肽。分子对接表明，这些肽可以通过氢键、盐桥、疏水相互作用、π-阳离子键和 π-π 键与 DPP-IV 相互作用。山核桃 DPP-IV 抑制肽在热处理、pH 处理或体外胃肠消化过程中表现出更好的稳定性。
