Isolation and identification of zinc-chelating peptides from sea cucumber (Stichopus japonicus) protein hydrolysate

Xiaoyang Liu, Zixu Wang, Jing Zhang, Liang Song, Deyang Li, Zixuan Wu, Beiwei Zhu, Yoshimasa Nakamura, Fereidoon Shahidi, Chenxu Yu, Dayong Zhou

Research output: Contribution to journalArticle

Abstract

BACKGROUND: Zinc is known to play an essential role in the biological activities in the human body. In this study, a zinc-chelating peptide (ZCP) produced by Alcalase-assisted hydrolysis of the body wall of sea cucumber was isolated and identified. The ZCP was purified stepwise by ultrafiltration, anion-exchange chromatography, and gel filtration chromatography, in conjunction with ultraviolet–visual (UV–visual) spectrophotometry, which was used to analyze each purified fraction. RESULTS: Analysis of the purified ZCP revealed that its zinc-chelating ability was 33.31%. Analysis of isothermal titration calorimetry suggested that the binding of ZCP and zinc (N ≈ 2) was endothermic, with weak binding affinity. Fourier transform infrared spectroscopy spectra (FTIR) indicated that carboxylic and amide groups in ZCP were the primary binding sites of Zn. Sequencing the result by ultra-performance liquid chromatography-quadrupole/time of flight mass spectrometry (UPLC-Q-TOF-MS/MS) showed that a representative ZCP had the sequence WLTPTYPE with a molecular weight of 1005.5 Da. CONCLUSION: These results provide a promising foundation for the production of zinc supplements from sea-cucumber-derived ZCPs.

Original languageEnglish
JournalJournal of the Science of Food and Agriculture
DOIs
Publication statusAccepted/In press - Jan 1 2019

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Keywords

  • hydrolysate
  • peptide sequencing
  • purification
  • sea cucumber
  • zinc-chelating peptides

ASJC Scopus subject areas

  • Biotechnology
  • Food Science
  • Agronomy and Crop Science
  • Nutrition and Dietetics

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