Novel Insights into Ethanol-Soluble Oyster Peptide–Zinc-Chelating Agents: Structural Characterization, Chelation Mechanism, and Potential Protection on MEHP-Induced Leydig Cells
Zhen Lu,
Qianqian Huang,
Xiaoming Qin,
Fujia Chen,
Enzhong Li,
Haisheng Lin
Affiliations
Zhen Lu
Guangdong Provincial Key Laboratory of Aquatic Products Processing and Safety, College of Food Science and Technology, National Research and Development Branch Center for Shellfish Processing, Guangdong Provincial Engineering Technology Research Center of Seafood, Guangdong Ocean University, Zhanjiang 524088, China
Qianqian Huang
Guangdong Provincial Key Laboratory of Aquatic Products Processing and Safety, College of Food Science and Technology, National Research and Development Branch Center for Shellfish Processing, Guangdong Provincial Engineering Technology Research Center of Seafood, Guangdong Ocean University, Zhanjiang 524088, China
Xiaoming Qin
Guangdong Provincial Key Laboratory of Aquatic Products Processing and Safety, College of Food Science and Technology, National Research and Development Branch Center for Shellfish Processing, Guangdong Provincial Engineering Technology Research Center of Seafood, Guangdong Ocean University, Zhanjiang 524088, China
Fujia Chen
School of Biological and Food Processing Engineering, Huanghuai University, Zhumadian 463000, China
Enzhong Li
School of Biological and Food Processing Engineering, Huanghuai University, Zhumadian 463000, China
Haisheng Lin
Guangdong Provincial Key Laboratory of Aquatic Products Processing and Safety, College of Food Science and Technology, National Research and Development Branch Center for Shellfish Processing, Guangdong Provincial Engineering Technology Research Center of Seafood, Guangdong Ocean University, Zhanjiang 524088, China
Numerous studies have reported that mono-(2-ethylhexyl) phthalate (MEHP) (bioactive metabolite of Di(2-ethylhexyl) phthalate) has inhibitory effects on Leydig cells. This study aims to prepare an oyster peptide–zinc complex (PEP-Zn) to alleviate MEHP-induced damage in Leydig cells. Zinc-binding peptides were obtained through the following processes: zinc-immobilized affinity chromatography (IMAC-Zn2+), liquid chromatography–mass spectrometry technology (LC-MS/MS) analysis, molecular docking, molecular dynamic simulation, and structural characterization. Then, the Zn-binding peptide (PEP) named Glu—His—Ala—Pro—Asn—His—Asp—Asn—Pro—Gly—Asp—Leu (EHAPNHDNPGDL) was identified. EHAPNHDNPGDL showed the highest zinc-chelating ability of 49.74 ± 1.44%, which was higher than that of the ethanol-soluble oyster peptides (27.50 ± 0.41%). In the EHAPNHDNPGDL-Zn complex, Asn-5, Asp-7, Asn-8, His-2, and Asp-11 played an important role in binding to the zinc ion. Additionally, EHAPNHDNPGDL-Zn was found to increase the cell viability, significantly increase the relative activity of antioxidant enzymes and testosterone content, and decrease malondialdehyde (MDA) content in MEHP-induced TM3 cells. The results also indicated that EHAPNHDNPGDL-Zn could alleviate MEHP-induced apoptosis by reducing the protein level of p53, p21, and Bax, and increasing the protein level of Bcl-2. These results indicate that the zinc-chelating peptides derived from oyster peptides could be used as a potential dietary zinc supplement.
