A Unique Capsular Polysaccharide Structure from the Psychrophilic Marine Bacterium Colwellia psychrerythraea 34H That Mimics Antifreeze (Glyco)proteins
A Unique Capsular Polysaccharide Structure from the Psychrophilic Marine Bacterium Colwellia psychrerythraea 34H That Mimics Antifreeze (Glyco)proteins
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DOI：
10.1021/ja5075954
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发表时间：
2015-01-14
影响因子：
15
通讯作者：
Corsaro, M. Michela
中科院分区：
文献类型：
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作者：
Carillo, Sara;Casillo, Angela;Corsaro, M. Michela
极地地区的低温和高海拔环境，特别是冰冷的栖息地，对许多微生物提出了挑战。它们在冰点以下的条件下生存的能力意味着产生了赋予低温耐受性的化合物。Colwellia psychrerythraea 34 H是一种从北极地区海洋沉积物中分离的γ-变形杆菌，为研究寒冷环境中的生命提供了一个模型。我们在这里报告的鉴定和详细的分子一级和二级结构的荚膜多糖从C。Psychrythraea H-34细胞。当细胞被苯酚/水提取时，聚合物被分离在水层中，并通过一维和二维NMR光谱与化学分析一起表征。还进行了分子力学和动力学计算。该多糖由一个含有两个氨基糖和两个带有苏氨酸取代基的糖醛酸的四糖重复单元组成。这种独特的多糖的结构特征类似于抗冻蛋白和糖蛋白中存在的那些。这些结果表明，C. psychrerythraea来殖民冰冻的海洋环境。
The low temperatures of polar regions and high-altitude environments, especially icy habitats, present challenges for many microorganisms. Their ability to live under subfreezing conditions implies the production of compounds conferring cryotolerance. Colwellia psychrerythraea 34H, a gamma-proteobacterium isolated from subzero Arctic marine sediments, provides a model for the study of life in cold environments. We report here the identification and detailed molecular primary and secondary structures of capsular polysaccharide from C. psychrerythraea H-34 cells. The polymer was isolated in the water layer when cells were extracted by phenol/water and characterized by one- and two-dimensional NMR spectroscopy together with chemical analysis. Molecular mechanics and dynamics calculations were also performed. The polysaccharide consists of a tetrasaccharidic repeating unit containing two amino sugars and two uronic acids bearing threonine as substituent. The structural features of this unique polysaccharide resemble those present in antifreeze proteins and glycoproteins. These results suggest a possible correlation between the capsule structure and the ability of C. psychrerythraea to colonize subfreezing marine environments.