Department of Life Sciences and Food for Health Ireland (FHI), University of Limerick, Castletroy, Limerick, Ireland.
Food Chem. 2013 Nov 1;141(1):644-53. doi: 10.1016/j.foodchem.2013.02.115. Epub 2013 Mar 7.
Xanthine oxidase (XO) and dipeptidyl peptidase IV (DPP-IV) inhibition by amino acids and dipeptides was studied. Trp and Trp-containing dipeptides (Arg-Trp, Trp-Val, Val-Trp, Lys-Trp and Ile-Trp) inhibited XO. Three amino acids (Met, Leu and Trp) and eight dipeptides (Phe-Leu, Trp-Val, His-Leu, Glu-Lys, Ala-Leu, Val-Ala, Ser-Leu and Gly-Leu) inhibited DPP-IV. Trp and Trp-Val were multifunctional inhibitors of XO and DPP-IV. Lineweaver and Burk analysis showed that Trp was a non-competitive inhibitor of XO and a competitive inhibitor of DPP-IV. Molecular docking with Autodock Vina was used to better understand the interaction of the peptides with the active site of the enzyme. Because of the non-competitive inhibition observed, docking of Trp-Val to the secondary binding sites of XO and DPP-IV is required. Trp-Val was predicted to be intestinally neutral (between 25% and 75% peptide remaining after 60 min simulated intestinal digestion). These results are of significance for the reduction of reactive oxygen species (ROS) and the increase of the half-life of incretins by food-derived peptides.
研究了氨基酸和二肽对黄嘌呤氧化酶 (XO) 和二肽基肽酶 IV (DPP-IV) 的抑制作用。色氨酸和含色氨酸的二肽 (Arg-Trp、Trp-Val、Val-Trp、Lys-Trp 和 Ile-Trp) 抑制 XO。三种氨基酸 (Met、Leu 和 Trp) 和八种二肽 (Phe-Leu、Trp-Val、His-Leu、Glu-Lys、Ala-Leu、Val-Ala、Ser-Leu 和 Gly-Leu) 抑制 DPP-IV。色氨酸和 Trp-Val 是 XO 和 DPP-IV 的多功能抑制剂。Lineweaver 和 Burk 分析表明，色氨酸是 XO 的非竞争性抑制剂和 DPP-IV 的竞争性抑制剂。使用 Autodock Vina 进行分子对接，以更好地了解肽与酶活性位点的相互作用。由于观察到非竞争性抑制，需要将 Trp-Val 对接至 XO 和 DPP-IV 的次级结合位点。预测 Trp-Val 在肠道中呈中性 (模拟肠道消化 60 分钟后剩余的肽在 25%到 75%之间)。这些结果对于通过食物来源的肽减少活性氧 (ROS) 和增加肠降胰岛素半衰期具有重要意义。
