去糖基化对水溶澳洲坚果糖肽结构和抗氧化性的影响  

Effect of deglycosylation on the structure and antioxidant activity ofwater-soluble macadamia glycopeptide

作　　者：向媛嫄 王文林 宋海云 黄雪松[1] XIANG Yuanyuan;WANG Wenlin;SONG Haiyun;HUANG Xuesong(College of Science and Engineering,Jinan University,Guangzhou 510632,China;Guangxi South Subtropical Agricultural Science Research Institute,Chongzuo 532415,China)

机构地区：[1]暨南大学理工学院,广东广州510632 [2]广西南亚热带农业科学研究所,广西崇左532415

出　　处：《食品与发酵工业》2021年第11期98-103,共6页Food and Fermentation Industries

基　　金：潮州市科技计划项目(2020ZX25);桂农科(2020YM48)。

摘　　要：为深入了解O-糖链对澳洲坚果糖肽结构和性质的影响,先从澳洲坚果油粕粉中分离纯化澳洲坚果糖肽(macadamia glycopeptide,MGP)、β-消除法脱糖链获得多肽(macadamia glycopeptide peptide,MGPP)后,用Tricine-甘油SDS-PAGE测定其分子质量;比较去糖基化前后糖肽的二级结构、热变性温度、空间结构的差异;采用3种方法(DPPH自由基的清除率、·OH清除率、还原能力)考察了MGP和MGPP的体外抗氧化活性。结果表明,MGP和MGPP都为均一组分,分子质量分别约为12 kDa和9 kDa;糖苷键为O型;β-消除反应后肽链二级结构中α-螺旋、β-折叠减少,热变性温度降低,空间结构变得杂乱无序,抗氧化活性显著降低。综上所述,O-糖基化会影响MGP二级结构和空间结构,从而影响肽链的热稳定性和抗氧化活性。To understand the influence of O-glycan on the structure and properties of macadamia glycopeptide,the glycopeptide was separated and purified from the macadamia defatted powder and named MGP.O-glycan linked with MGP was released byβ-elimination and the MGPP without the glycan was obtained.The molecular mass of MGPP was determined by tricine-glycerol SDS-PAGE.The differences in secondary structure,thermal denaturation temperature and spatial structure were compared between MGP and MGPP.The antioxidant abilities of MGP and MGPP were evaluated by the reducing power,the scavenging effects for DPPH,·OH radicals.The results showed that both MGP and MGPP were homogeneous components with molecular masses of approximately 12 kDa and 9 kDa.The glycopeptide linkage was mainly O-glycopeptide.After theβ-elimination reactionα-helix andβ-sheets in the secondary structure of the peptide chain were reduced.Moreover,the thermal denaturation temperature was lower,the molecular spatial structure became disorderly and the antioxidant activity was significantly reduced.In summary,O-glycosylation had a significant change in the secondary structure and spatial structure of MGP,thereby affecting the functional characteristics of the peptide chain.

关 键 词：澳洲坚果 糖肽 二级结构 O-糖链 抗氧化 

分 类 号：TS255.6[轻工技术与工程—农产品加工及贮藏工程]