Characterization and solution properties of a new exopolysaccharide excreted by the bacterium Alteromonas sp strain 1644
Characterization and solution properties of a new exopolysaccharide excreted by the bacterium Alteromonas sp strain 1644
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DOI：
10.1016/0141-8130(95)01038-6
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发表时间：
1996-02-01
影响因子：
8.2
通讯作者：
Rinaudo, M
中科院分区：
文献类型：
--
作者：
Bozzi, L;Milas, M;Rinaudo, M
本文对一种新型细菌胞外多糖进行了研究。考虑聚合物的离子性质与第一个结构结果有关。该多糖是一种电荷参数为1.33的羧基聚电解质，与一价离子和镁离子具有常见的聚电解质性质。相反，它对二价离子Ca~(2+)、Sr~(2+)和Ba~(2+)的亲和力比静电理论预测的要大。在溶液中，多糖经历局部构象转变，这与每个羧基结合的二价离子的数量有关。这种相互作用主要是分子内过程。用光散射法和粘度法研究了聚合链的尺寸。本征驻留长度L(P)等于80+/-5埃，这使得该聚合物被归类为半刚性链。
This paper concerns the study of a new bacterial exopolysaccharide. The ionic properties of the polymer are considered in relation to the first structural results. This polysaccharide is a carboxylic polyelectrolyte with a charge parameter of 1.33, and exhibits usual polyelectrolyte properties with monovalent and Mg2+ ions. In contrast, its affinity for the divalent ions Ca2+, Sr2+ and Ba2+ is greater than predicted from electrostatic theory. In solution, the polysaccharide undergoes a local conformational transition related to the number of divalent ions bound per carboxylic group. This interaction is mainly an intramolecular process. The dimensions of the polymeric chain were also considered using light-scattering and viscometric measurements. The intrinsic persistence length L(p) is equal to 80 +/- 5 Angstrom and allows this polymer to be classified as a semi-rigid chain.