School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China.
Carbohydr Res. 2010 Mar 30;345(5):649-55. doi: 10.1016/j.carres.2009.11.030. Epub 2009 Dec 4.
A glycosaminoglycan from sea cucumber Thelenata anana (THG) was isolated as a polymer of molecular weight of around 70 kDa. Its low molecular weight derivatives were first prepared by free radical depolymerization with hydrogen peroxide in the presence of copper(II) ion. The parameters of the process were investigated by a high-performance gel permeation chromatography. Analyses of chemical composition and molecular weight distribution indicated that the fragmentation of the main-chain of THG occurred randomly, obeyed pseudo first-order kinetics, and produced species with rather narrow and unimodal distribution of molar mass. The characterization of different molecular weight fractions was investigated by using viscometry and atomic force microscopy (AFM). Analysis of molecular weight and intrinsic viscosity in terms of the known theories for unperturbed wormlike cylinder yielded 1201+/-110 nm(-1), 15.3+/-1.5 nm, and 1.5+/-0.3 nm for molar mass per unit contour length M(L), persistence length q, and diameter d, respectively. The M(L) and d values were approximately consistent with those observed by AFM. The present data suggest that THG may dissolve in 0.1M aqueous NaCl as single-stranded helical chains.
海参硫酸软骨素的分离及其自由基降解产物的分子量分布研究 从海参（Thelenata anana）中分离得到一种相对分子质量约为 70 kDa 的硫酸软骨素（THG）。首先采用自由基降解法，以过氧化氢为降解剂，在铜(II)离子存在的条件下，制备了 THG 的低相对分子质量衍生物。通过高效凝胶渗透色谱法对降解过程的参数进行了研究。化学组成和相对分子质量分布分析表明，THG 主链的断裂是随机发生的，符合准一级反应动力学，且产物的相对分子质量分布较窄，呈单峰分布。采用黏度法和原子力显微镜（AFM）对不同相对分子质量级分进行了表征。根据无扰蠕虫状链理论对相对分子质量和特性黏数的分析表明，THG 的单位轮廓长度摩尔质量 ML 为 1201+/-110nm-1，无扰链卷曲度 q 为 15.3+/-1.5nm，直径 d 为 1.5+/-0.3nm。ML 和 d 值与 AFM 的观察结果基本一致。这些数据表明，THG 在 0.1M 氯化钠水溶液中可能以单链螺旋的形式存在。
