National Engineering Research Center of Seafood, School of Food Science and Technology , Dalian Polytechnic University , 1 Qinggongyuan , Ganjingzi District, Dalian , Liaoning 116034 , People's Republic of China.
J Agric Food Chem. 2020 Feb 19;68(7):2232-2239. doi: 10.1021/acs.jafc.9b07770. Epub 2020 Feb 11.
An antioxidant peptide derived from egg white, Asp-His-Thr-Lys-Glu (DHTKE), possesses specific amino acids related to zinc delivery. This study aimed to demonstrate the molecular basis of interactions between the egg white peptide (DHTKE) and zinc ions and investigate the effect of the DHTKE-Zn complex on zinc delivery through the gastrointestinal system. Approximately one DHTKE molecule can bind one zinc ion ( = 1.048 ± 0.085) through its carboxyl, amino, and imidazole nitrogen groups on Asp, His, and Glu. The formed DHTKE-Zn complex presented uniformly distributed globular particles with a particle size of 100-500 nm and underwent dissociation and re-chelation during gastrointestinal digestion. Moreover, the DHTKE peptide mostly remained stable, with a retention rate of 98.32% under gastrointestinal digestion, although one degradation product (DHTK) was identified by nanoscale liquid chromatography-electrospray ionization-tandem mass spectrometry in the gastrointestinal digests; the effectiveness of DHTKE-Zn digests on enhancing absorption of zinc was comparable to that of the initial complex.
一种源自蛋清的抗氧化肽，Asp-His-Thr-Lys-Glu (DHTKE)，具有与锌输送相关的特定氨基酸。本研究旨在阐明蛋清肽 (DHTKE) 与锌离子相互作用的分子基础，并研究 DHTKE-Zn 配合物通过胃肠道系统输送锌的效果。大约一个 DHTKE 分子可以通过其在 Asp、His 和 Glu 上的羧基、氨基和咪唑氮结合一个锌离子（= 1.048 ± 0.085）。形成的 DHTKE-Zn 配合物呈现出均匀分布的球形颗粒，粒径为 100-500nm，并在胃肠道消化过程中发生解离和再螯合。此外，尽管在胃肠道消化物中通过纳升液相色谱-电喷雾电离-串联质谱鉴定出一个降解产物 (DHTK)，但 DHTKE 肽在胃肠道消化过程中大部分保持稳定，保留率为 98.32%；DHTKE-Zn 消化物对增强锌吸收的效果与初始配合物相当。
