玉米肽钙螯合物的结构表征和螯合机制  

Structural Characterization and Chelation Mechanism of Corn Peptide Calcium Chelate

作　　者：吴晗硕 任杰 付少委 张新雪 冯志远 李书国[1] 刘文颖[2] Wu Hanshuo;Ren Jie;Fu Shaowei;Zhang Xinxue;Feng Zhiyuan;Li Shuguo;Liu Wenying(College of Food Science and Biology,Hebei University of Science and Technology,Shijiazhuang 050091;Beijing Engineering Research Center of Protein and Functional Peptides,China National Research Institute of Food and Fermentation Industries,Beijing 100015)

机构地区：[1]河北科技大学食品与生物学院,石家庄050091 [2]中国食品发酵工业研究院、北京市蛋白功能肽工程技术研究中心,北京100015

出　　处：《中国食品学报》2024年第10期115-123,共9页Journal of Chinese Institute Of Food Science and Technology

基　　金：宁夏回族自治区重点研发计划项目(2021BEG02027)。

摘　　要：为探究玉米肽钙螯合物的结构特性和肽段与钙离子的结合位点,以玉米肽和氯化钙为原料制备玉米肽钙螯合物,通过傅里叶变换红外光谱、核磁共振光谱分析、热重分析和质谱分析对玉米肽钙螯合物的结构进行表征,并用分子对接技术模拟玉米肽肽段和钙离子结合位点。傅里叶红外光谱测定结果表明:玉米肽和钙离子螯合后,酰胺I带和酰胺II带红移和N-H键蓝移,COO-的伸缩振动于1400 cm-1左右产生红移。核磁共振光谱分析显示,玉米肽钙螯合后吸收峰普遍减弱和消失。热重显示降解阶段降解率分别为43.26%和65.05%,残留率显著提高,由19%提高到38.6%。质谱分析得出7条肽段序列,选择两条疏水性氨基酸较多的肽段和钙离子做分子对接,模拟结合位点。Asn-Gln-Phe-Ser-Leu-Ile-Asn-Pro-Val-Leu-Ser-Arg(NQFSLINPVLSR)、Ser-Leu-Ile-Asn-Pro-Val-Leu-Ser-Arg-Gln-Gln-Pro-Ile-Val-Gly-Gly-Ala(SLINPVLSRQQPIVGGA)和钙离子的结合能分别为-68.08 kJ/mol和-67.56 kJ/mol。推测多肽氨基酸残基上的羧基氧原子和氨基是螯合钙离子的主要位点,玉米肽和钙螯合后热稳定性较玉米肽显著增强。To investigate the structure characteristics of the corn peptide calcium chelate and the binding sites of peptides with calcium ions,corn peptide calcium chelate was prepared using corn peptides and calcium chloride as raw materials.The structures of corn peptide calcium chelate were characterized by Fourier transform infrared spectrometer(FTIR),nuclear magnetic resonance(NMR),thermogravimetry analysis(TG),and mass spectrometry,and the binding sites of peptides and calcium ions were simulated by molecular docking technique.FTIR indicated that after the chelation of corn peptides with calcium ions,the amide I and amide II bands exhibited the red-shift and the N-H bond showed the blue-shift,and exhibited the red-shift at around 1400 cm-1 because of stretching vibration of COO-.NMR showed that the absorption peak of corn peptide calcium chelate generally weakened and disappeared.The TG result showed that the degradation rates during the degradation stage were 43.26%and 65.05%,respectively,and the residual rate significantly increased from 19%to 38.6%.Seven peptide sequences were identified through mass spectrometry analysis.Two peptide segments with more hydrophobic amino acids were selected for molecular docking with calcium ions to simulate binding sites.The binding energies of Asn-Gln-Phe-Ser-Leu-Ile-Asn-Pro-Val-Leu-Ser-Arg(NQFSLINPVLSR)and Ser-Leu-Ile-Asn-Pro-Val-Leu-Ser-Arg-Gln-Gln-Pro-Ile-Val-Gly-Gly-Ala(SLINPVLSRQQPIVGGA)with calcium ions were-68.08 kJ/mol and-67.56 kJ/mol,respectively.It is speculated that the carboxyl oxygen atom and the amino groups on the amino acid residues of peptides were the main binding sites for chelating calcium ions.The thermal stability of corn peptide calcium chelate was significantly enhanced compared to corn peptides.

关 键 词：玉米肽 钙 螯合 结构表征 分子对接 

分 类 号：TS201.2[轻工技术与工程—食品科学]