摘要 以罗非鱼皮为原料,采用5种蛋白酶对其进行酶解,以罗非鱼皮酶解物多肽(tilapia skin protein peptides,TSPP)的Fe2+结合率为指标,筛选出Fe2+结合率最高的TSPP;探究结合时间、pH值、温度对结合率的影响以及TSPP结合Fe2+前后其荧光、紫外、红外等光谱的变化;对TSPP的分子质量分布、氨基酸的组成及其抗氧化活性进行测定。结果表明,罗非鱼皮蛋白经胰蛋白酶水解2 h后得到的TSPP,其Fe2+结合率最高;pH 5、温度37℃、时间90 min为最佳结合条件;TSPP结合Fe2+后,肽链发生折叠,其内源性荧光强度下降,紫外特征性吸收带出现红移,肽链中的氨基、羰基、羧基可能是Fe2+的结合位点;TSPP中的Fe2+结合活性肽,其分子质量大约在500~3000 Da之间,且肽链富含Asp、Glu、Gly、Arg及Pro等氨基酸;各酶解物均具有一定的抗氧化能力,TSPP结合Fe2+前后,其抗氧化能力无显著性变化;此外,虽然TSPP的抗氧化能力明显低于谷胱甘肽,但其Fe2+结合活性明显高于谷胱甘肽。结果显示,TSPP具有良好的Fe2+结合活性,有望发展为新型的铁元素膳食补充剂。 In this research,we optimized the preparation conditions of Fe2+-chelating peptides from tilapia skin protein,and we structurally characterize the complex.Five commercial proteases were screened for the highest Fe2+-chelating rate of peptides.The effects of chelating time,pH and temperature on the Fe2+-chelating rate were evaluated,and the changes in the fluorescence,ultraviolet and infrared spectra of the peptides were examined before and after chelating with Fe2+.In addition,the molecular mass distribution,amino acid composition and antioxidant activity of the peptides were measured.The results showed that the peptides obtained after 2 h of hydrolysis with trypsin had the highest Fe2+-chelating rate.The optimal chelating conditions were pH 5,37℃,and 90 min.Chelating with Fe2+resulted in folding of the peptide chain,decreased intrinsic fluorescence intensity,and red shift of the characteristic ultraviolet absorption band.Fe2+was likely bound to the amino,carbonyl and carboxyl groups of the peptides.The molecular mass of the Fe2+-chelating peptides was about 500–3000 Da,and the peptide chains were rich in Asp,Glu,Gly,Arg and Pro.All hydrolysates had antioxidant capacity.The antioxidant capacity was not significantly changed after chelating with Fe2+.Although the antioxidant capacity of the trypsinic hydrolysate was significantly lower than that of glutathione,the Fe2+-chelating activity was significantly higher than that of glutathione.The results showed that the peptides in the hydrolysate had excellent Fe2+-chelating activity suggesting the potential to be developed into a new dietary iron supplement.
出处 《食品科学》 EI CAS CSCD 北大核心 2021年第8期157-164,共8页 Food Science
基金 茂名市引进创新创业团队项目(200201095834980) 现代农业产业技术体系建设专项(CARS-46) 广东省基础与应用基础研究基金项目(2019A1515011588) 广东省科技创新战略专项资金(纵向协同管理方向)计划项目(2018S0044) 广东省重点领域研发计划项目(2020B020226005 2020B1111030004) 中国水产科学研究院基本科研业务费资助项目(2020TD69) 中国水产科学研究院南海水产研究所中央级公益性科研院所基本科研业务费专项(2021SD06)。
关键词 罗非鱼皮蛋白 肽-Fe2+结合物 结合条件 结构特征 生物活性 tilapia skin protein peptide-Fe2+complexes chelating conditions structural characteristics biological activity
