Ikeda F, Shuto H, Saito T, Fukui T, Tomita K
Eur J Biochem. 1982 Apr 1;123(2):437-45. doi: 10.1111/j.1432-1033.1982.tb19787.x.
A weakly acidic polysaccharide was purified from the extracellular zoogloeal matrix produced by Zoogloeal ramigera 115. The purified polysaccharide was homogeneous as judged by sedimentation analysis, and the average molecular weight was estimated to be about 10(5) by gel permeation chromatography of the fully methylated preparation. The polysaccharide was composed of D-glucose, D-galactose and pyruvic acid in an approximate molar ratio 11:3:1.5. On the basis of methylation, periodate oxidation, Smith degradation and partial hydrolysis, the following highly branched structure was deduced for the polysaccharide: a long chain mainly consisting of beta 1 leads to 4-linked glucose residues branching at the C-3 or C-6 position of galactose residues which are present in beta 1 leads to 4 or beta 1 leads to 3 linkages as the minor component of the long chain; pyruvic acid residues, the sole acidic component, are linked to the nonreducing end and/or 1,3-linked glucose residues through 4,6-ketal linkages. The purified polysaccharide was not readily soluble in water and had a high affinity for several metallic ions (e.g, 0.25 mumol Fe3+/mg, and 0.17 mumol Fe2+ mg). Upon addition of metallic ions (1 mM) to a gelatinous aqueous solution of the polysaccharide (K+ form, 0.125%), more than 80% of it immediately coprecipitated out with them.
从生枝动胶菌115产生的胞外菌胶团基质中纯化出一种弱酸性多糖。通过沉降分析判断，纯化后的多糖是均一的，通过对完全甲基化产物进行凝胶渗透色谱法估计其平均分子量约为10⁵。该多糖由D-葡萄糖、D-半乳糖和丙酮酸组成，摩尔比约为11:3:1.5。基于甲基化、高碘酸盐氧化、史密斯降解和部分水解，推测该多糖具有以下高度分支的结构：一条长链主要由β-1,4-连接的葡萄糖残基组成，在半乳糖残基的C-3或C-6位置分支，半乳糖残基以β-1,4或β-1,3连接作为长链的次要成分；丙酮酸残基是唯一的酸性成分，通过4,6-缩酮键与非还原端和/或1,3-连接的葡萄糖残基相连。纯化后的多糖不易溶于水，对几种金属离子具有高亲和力（例如，0.25 μmol Fe³⁺/mg和0.17 μmol Fe²⁺/mg）。向多糖的凝胶状水溶液（K⁺形式，0.125%）中加入金属离子（1 mM）后，超过80%的多糖会立即与它们共沉淀出来。
