Engineering Research Center of Health Food Design & Nutrition Regulation, School of Life and Health Technology, Dongguan University of Technology, Dongguan 523808, China.
College of Biological Engineering, Dalian Polytechnic University, Dalian 116034, China.
J Agric Food Chem. 2023 May 10;71(18):6978-6986. doi: 10.1021/acs.jafc.3c00001. Epub 2023 May 2.
Casein-derived peptides are recognized as promising candidates for improving zinc bioavailability through the form of a peptide-zinc chelate. In the present work, a novel 11-residue peptide TEDELQDKIHP identified from casein hydrolysate in our previous study was synthesized to investigate the zinc chelation characteristics. Meanwhile, the digestion stability and transepithelial transport of TEDELQDKIHP-Zn were also investigated. The obtained results indicated that the carboxyl groups (from Asp and Glu), amino groups (from Lys and His), pyrrole nitrogen group of Pro, and imidazole nitrogen group of His were responsible for zinc chelation. The complexation with zinc resulted in a more ordered structure of TEDELQDKIHP-Zn. In terms of digestion stability, the chelate of TEDELQDKIHP-Zn could remain stable to a large extent after gastric (78.54 ± 0.14%) and intestinal digestion (70.18 ± 0.17%). Moreover, TEDELQDKIHP-Zn was proven to be a well-absorbed biological particle with a value higher than 1 × 10 cm/s, and it could be transported across the intestine epithelium through transcytosis. TEDELQDKIHP-Zn exhibited more bioavailable effects on zinc absorption and ALP activity than inorganic zinc sulfate.
酪蛋白衍生肽被认为是提高锌生物利用度的有前途的候选物，其形式为肽-锌螯合物。在本工作中，合成了一种从我们之前的研究中从酪蛋白水解物中鉴定出的 novel 11-residue peptide TEDELQDKIHP，以研究其锌螯合特性。同时，还研究了 TEDELQDKIHP-Zn 的消化稳定性和跨上皮转运。结果表明，羧基（来自 Asp 和 Glu）、氨基（来自 Lys 和 His）、Pro 的吡咯氮和 His 的咪唑氮是锌螯合的主要基团。与锌的络合导致 TEDELQDKIHP-Zn 的结构更加有序。在消化稳定性方面，TEDELQDKIHP-Zn 的螯合物在胃（78.54 ± 0.14%）和肠（70.18 ± 0.17%）消化后能够在很大程度上保持稳定。此外，证明 TEDELQDKIHP-Zn 是一种可吸收的生物颗粒，其值高于 1 × 10 cm/s，可以通过转胞吞作用穿过肠上皮细胞转运。TEDELQDKIHP-Zn 在锌吸收和 ALP 活性方面比无机硫酸锌具有更高的生物利用度。
