食品科学 ›› 2017, Vol. 38 ›› Issue (21): 49-54.doi: 10.7506/spkx1002-6630-201721008

• 基础研究 • 上一篇    下一篇

基于原子力显微镜和流变学特性的葛仙米多糖构象分析

莫开菊,程超,庄洋,陈美林,赵娜   

  1. (1.湖北民族学院生物科学与技术学院,湖北?恩施 445000;2.湖北民族学院?生物资源保护与利用湖北省重点实验室,湖北?恩施 445000)
  • 出版日期:2017-11-15 发布日期:2017-11-01
  • 基金资助:
    国家自然科学基金面上项目(31171670)

Conformational Analysis of Polysaccharide from Nostoc sphaeroides Kütz. Based on Atomic Force Microscope and Rheological Properties

MO Kaiju, CHENG Chao, ZHUANG Yang, CHEN Meilin, ZHAO Na   

  1. (1. School of Biological Science and Technology, Hubei University for Nationalities, Enshi 445000, China; 2. Hubei Key Laboratory of Biological Resource Conservation and Utilization, Hubei University for Nationalities, Enshi 445000, China)
  • Online:2017-11-15 Published:2017-11-01

摘要: 通过原子力显微镜观察葛仙米多糖的单分子形态,发现葛仙米多糖包括柔性分支链和刚性分支链,主要以带分支的柔性长链、无分支或分支较少的刚性分支链、3?条链缠绕而成的发散结构等形态存在,同时观察到部分分支链的单螺旋结构。葛仙米多糖主要以丰富分支的状态存在,可见螺旋结构,分支长度一般在200~600?nm,单分子直径在1.0?nm以内,在多链缠绕处高度为1.3~2.3?nm左右。流变学特性分析表明,葛仙米多糖能形成弱凝胶体系,说明多糖分子间能够交联,但交联度不高,证实葛仙米多糖具有柔性的多分支结构。

关键词: 原子力显微镜, 葛仙米, 多糖, 流变学, 链构象

Abstract: In this paper, the single-molecule morphology of polysaccharides extracted from Nostoc sphaeroides Kütz. was studied by atomic force microscopy. As a result, the polysaccharides were found to consist of flexible and rigid molecular chains and mainly exist in the form of flexible long chain with multi-branches, rigid chains with less or without branches and a divergent structure composed of three intertwined chains. Besides, a single helix for some of the branch chains was also found. The polysaccharides mainly existed in the conformation with abundant branches whose length was generally about 200–600 nm, the diameter of single molecules was within 1.0 nm, and the height of intertwined chains was about 1.3–2.3 nm. The rheological properties showed that the polysaccharides could form a weak gel, indicating that the polysaccharide molecules could be only slightly crosslinked. All rheological properties confirmed that the polysaccharides had multiple flexible branches.

Key words: atomic force microscopy, Nostoc sphaeroides Kütz., polysaccharide, rheological properties, chain conformation

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