食品科学 ›› 2019, Vol. 40 ›› Issue (24): 53-59.doi: 10.7506/spkx1002-6630-20190521-240

• 食品化学 • 上一篇    下一篇

大米球蛋白铜离子结合肽的鉴定及其螯合活性分析

邢常瑞,初晨露,张晓云,汪金燕,鞠兴荣,袁建   

  1. (南京财经大学食品科学与工程学院,江苏省现代粮食流通与安全协同创新中心,江苏高校粮油质量安全控制及深加工重点实验室,江苏 南京 210023)
  • 出版日期:2019-12-25 发布日期:2019-12-24
  • 基金资助:
    “十三五”国家重点研发计划重点专项(2017YFD0401404)

Identification and Metal Chelation Activity of a Copper-Binding Peptide from Rice Globulin Hydrolysate

XING Changrui, CHU Chenlu, ZHANG Xiaoyun, WANG Jinyan, JU Xingrong, YUAN Jian   

  1. (College of Food Science and Engineering, Collaborative Innovation Center for Modern Grain Circulation and Safety, Key Laboratory of Grains and Oils Quality Control and Processing, Nanjing University of Finance and Economics, Nanjing 210023, China)
  • Online:2019-12-25 Published:2019-12-24

摘要: 为分析大米球蛋白与金属元素的结合特性,通过分级提取方法得到4 种大米蛋白,并测定其金属元素含量。选取大米球蛋白经胃蛋白酶酶解,酶解液通过超滤方式进行纯化。将获得的水解液进行质谱检测,并通过软件分析得到23 条多肽序列,分子质量在725~1 409 Da之间。结合已报道的相关研究,分析得到多肽序列QGWSSSSE和YYGGEGSSSEQGY具有潜在金属螯合活性。通过人工合成这两条多肽序列,并选择乙二胺四乙酸(ethylenediaminetetraacetic acid,EDTA)、柠檬酸和金属硫蛋白作为参照物,比较它们与Cu2+的螯合活性。结果发现YYGGEGSSSEQGY螯合Cu2+效果比QGWSSSSE好,与Cu2+螯合的IC20为5.40 mmol/L,并且在低浓度范围与柠檬酸相当,比EDTA和金属硫蛋白差。进一步分析,这两条多肽与其他金属离子之间螯合活性发现,其与Fe2+结合更强。通过氨基酸分析,连续丝氨酸SS、SSS和SSSS可能与铜的螯合活性相关。

关键词: 大米球蛋白, 铜离子结合肽, 螯合活性

Abstract: Four rice proteins were obtained by sequential extraction, and their metal element contents were determined. Rice globulin was selected from these proteins for hydrolysis by pepsin, and the hydrolysate was purified by ultrafiltration. The fraction containing polypeptides was collected and detected by mass spectrometry (MS). A total of 23 polypeptides with molecular mass ranging from 725 to 1 409 Da were obtained through software analysis. Based on the data reported in the literature, the polypeptides QGWSSSSE and YYGGEGSSSEQGY may have potential metal chelation activity. The Cu2+ chelation activity of the two synthetic polypeptides was compared with that of EDTA, citric acid and metallothionein. It was found that YYGGEGSSSEQGY had a better Cu2+ chelation activity than QGWSSSSE. The IC20 of YYGGEGSSSEQGY was 5.40 mmol/L, which was comparable to that of citric acid in a low concentration range, but was worse than EDTA and metallothionein. Furthermore, these two polypeptides could more strongly bind Fe2+ than other metal ions. Amino acid composition analysis showed that continuous serine SS, SSS, and SSSS may be associated with the copper-binding activity.

Key words: rice globulin, copper-binding peptide, metal chelation activity

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