Title
Zinc-Chelating Mechanism of Sea Cucumber (Stichopus japonicus)-Derived Synthetic Peptides
Author
Xiaoyang Liu, Zixu Wang, Fawen Yin, Yuxin Liu, Ningbo Qin, Yoshimasa Nakamura, Fereidoon Shahidi, Chenxu Yu, Dayong Zhou, Beiwei Zhu
Year
2019
Journal
Marine Drugs
Abstract
In this study, three synthetic zinc-chelating peptides (ZCPs) derived from sea cucumber hydrolysates with limited or none of the common metal-chelating amino-acid residues were analyzed by flame atomic absorption spectroscopy, circular dichroism spectroscopy, size exclusion chromatography, zeta-potential, Fourier transform infrared spectroscopy, Raman spectroscopy and nuclear magnetic resonance spectroscopy. The amount of zinc bound to the ZCPs reached maximum values with ZCP:zinc at 1:1, and it was not further increased by additional zinc presence. The secondary structures of ZCPs were slightly altered, whereas no formation of multimers was observed. Furthermore, zinc increased the zeta-potential value by neutralizing the negatively charged residues. Only free carboxyl in C-terminus of ZCPs was identified as the primary binding site of zinc. These results provide the theoretical foundation to understand the mechanism of zinc chelation by peptides.
Full Article
Instrument
J-1500
Keywords
Circular dichroism, Secondary structure, Ligand binding, Biochemistry