外源氨基酸修饰的类蛋白反应对鸡肺抗氧化肽结构与功能的影响  

Effects of Exogenous Amino Acid Modified Plastein Reactions on the Structure and Functions of Antioxidant Peptides from Chicken Lung

作　　者：尹家琪 余军军 康明丽[3] 杨露 韩敏义[1,2,4] 徐幸莲 Yin Jiaqi;Yu Junjun;Kang Mingli;Yang Lu;Han Minyi;Xu Xinglian(College of Food Technology,Nanjing Agricultural University,Nanjing 210095;Key Laboratory of Meat Products Processing,Ministry of Agriculture,Jiangsu Collaborative Innovation Center of Meat Production and Processing,Quality and Safety Control,Nanjing 210095;College of Food Science and Biology,Hebei University of Science and Technology,Shijiazhuang 050018;Wens Food Group Co.,LTD.,Yunfu 527400,Guangdong)

机构地区：[1]南京农业大学食品科技学院,南京210095 [2]农业部肉品加工重点实验室、江苏省肉类生产与加工质量安全控制协同创新中心,南京210095 [3]河北科技大学食品与生物学院,石家庄050018 [4]温氏食品集团股份有限公司,广东云浮527400

出　　处：《中国食品学报》2023年第4期22-34,共13页Journal of Chinese Institute Of Food Science and Technology

基　　金：国家自然科学基金项目(32272252);温氏股份科技重大专项(WENS-2020-1-ZDZX-007);国家现代农业产业技术体系资助项目(CARS-41);江苏高校优势学科建设工程资助项目(PAPD)。

摘　　要：天然生物活性肽往往功能特性和热稳定性差。为改善鸡肺肽的抗氧化能力和热稳定性,采用胃蛋白酶和外源氨基酸参与的类蛋白反应对鸡肺抗氧化肽进行处理。利用高效液相色谱测定反应前、后的分子量变化,利用紫外光谱、荧光光谱、X射线衍射图谱、扫描电镜对反应前、后物质的性质进行表征,通过傅里叶变换红外光谱、圆二色光谱分析蛋白质二级结构的变化。结果表明,添加3%的半胱氨酸处理后其DPPH·自由基清除率、Fe2+螯合能力和·OH清除率分别提升了51.85%,31.11%、31.30%,热变性温度从122.06℃提至136.15℃。类蛋白反应使产物的分子量和表面疏水性增大。紫外和荧光光谱表明氨基酸微环境的变化改善了抗氧化活性。X射线衍射图谱显示类蛋白反应发生后样品主衍射峰变宽,强度降低。扫描电镜结果表明反应涉及分子的水解与再聚合。红外光谱和圆二色光谱结果显示:多肽分子舒展,疏水基团暴露,这可能是多肽抗氧化能力改善的原因。综上,类蛋白反应改变了蛋白质的二级和三级结构,从而有效改善了生物活性肽的抗氧化能力与热稳定性。Natural bioactive peptides often have poor functional properties and thermal stability,in order to improve the antioxidant ability and thermal stability of chicken lung peptides,plastein reaction involving pepsin and exogenous amino acids was used to treat peptides from chicken lung.High performance liquid chromatography(HPLC)was applied to compare the molecular weight changes before and after the reaction,while the properties of the substances were characterized by UV spectra,fluorescence spectrum,X-ray diffraction spectrum,scanning electron micrographs(SEM).Meanwhile,Fourier transform infrared spectrum(FTIR)and circular dichroism(CD)spectrum were employed to explore the changes of the secondary structure of peptide and plastein.The results showed:Firstly,the DPPHo free radical scavenging rate,chelating ability of Fe2+and·OH scavenging rate increased by 51.85%,31.11%and 31.30%while the thermal denaturation temperature raised from 122.06℃to 136.15℃after 3%Cysteine supplementation.Secondly,the molecular weight and surface hydrophobicity increased,UV and fluorescence spectra showed that the changes of amino acid microenvironment improved the antioxidant activity.Thirdly,the X-ray diffraction pattern revealed that the main diffraction peak widened but the intensity decreased after the reaction,the SEM results displayed that the process involved hydrolysis and repolymerization of molecules.Finally,the results of FTIR and CD showed that the peptide molecules were stretched and the hydrophobic groups were exposed,which might be the reason for the improved antioxidant capacity of the peptides.In summary,plastein reactions changed the secondary and tertiary structures of proteins,thus effectively improving the antioxidant capacity and thermal stability of bioactive peptides.

关 键 词：抗氧化肽 氨基酸修饰 类蛋白反应 结构 

分 类 号：TS201.2[轻工技术与工程—食品科学]