食品科学 ›› 2018, Vol. 39 ›› Issue (6): 63-68.doi: 10.7506/spkx1002-6630-201806011

• 食品化学 • 上一篇    下一篇

酪蛋白铁螯合肽的分离纯化及结构解析

纪晓雯,王志耕*,阚文翰,梅林,薛秀恒   

  1. (安徽农业大学茶与食品科技学院,安徽省农产品加工工程实验室,安徽?合肥 230036)
  • 出版日期:2018-03-25 发布日期:2018-03-14
  • 基金资助:
    安徽省科技计划项目(12Z0102055)

Isolation, Purification and Structural Analysis of Iron-Binding Peptides from Casein Hydrolysate

JI Xiaowen, WANG Zhigeng*, KAN Wenhan, MEI Lin, XUE Xiuheng   

  1. (Engineering Laboratory of Agricultural Products Processing of Anhui Province, College of Tea and Food Science and Technology, Anhui Agriculture University, Hefei 230036, China)
  • Online:2018-03-25 Published:2018-03-14

摘要: 为探讨酪蛋白铁螯合肽螯合机制,对比固定金属亲和层析和阴离子交换层析初分再结合Sephacryl S-100 HR凝胶过滤层析分离对酪蛋白铁螯合肽进行分离纯化效果,并通过紫外光谱、傅里叶变换红外光谱和液相色谱-质谱联用方法对纯化后多肽结构进行解析。结果表明,亲和层析与凝胶过滤层析法结合分离得到的酪蛋白多肽组分的铁螯合活性高于阴离子交换层析组分,其铁螯合活性可达39.56?μg/mg。紫外光谱和红外光谱检测证明酪蛋白肽和铁离子形成螯合物,羧基位点螯合前后发生变化;质谱鉴定出3?条肽段,氨基酸序列为HIQKEDVPSER、ITVDDKHYQK和TRLHPVQER,肽段中Glu、Asp、Gln出现频率高,侧链均含有C=O键,推测多肽的羰基位是铁离子的主要螯合位点。

关键词: 酪蛋白, 铁, 螯合肽, 纯化, 结构

Abstract: Iron-binding peptides from tryptic casein hydrolysate were separated by immobilized metal affinity chromatography or anion exchange chromatography followed by purification by Sephacryl S-100 HR gel chromatography. The purified peptide was structurally elucidated by UV-Vis spectroscopy, Fourier transform infrared (FT-IR) spectroscopy and liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results showed that a fraction with high iron chelating capacity of 39.56 μg/mg purified by affinity chromatography followed by gel filtration chromatography was obtained, which was better than that purified by anion exchange chromatography. The formation of peptide-iron chelate was confirmed by UV-Vis and FT-IR spectra, and some changes at the carboxyl site occurred after chelating. Besides, three peptide fragments were identified by MS, whose amino acid sequences were HIQKEDVPSER, ITVDDKHYQK and TRLHPVQER, respectively. Asp, Glu and Gln were found to be abundant in these peptide fragments with each of them containing carbonyl group, suggesting that the carbonyl site of the peptide is among the main iron-binding sites.

Key words: casein, iron, chelating peptide, purification, structure

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