STRUCTURE OF A NOVEL OLIGOSACCHARIDE-MYCOSPORINE-AMINO ACID ULTRAVIOLET A/B SUNSCREEN PIGMENT FROM THE TERRESTRIAL CYANOBACTERIUM NOSTOC COMMUNE
STRUCTURE OF A NOVEL OLIGOSACCHARIDE-MYCOSPORINE-AMINO ACID ULTRAVIOLET A/B SUNSCREEN PIGMENT FROM THE TERRESTRIAL CYANOBACTERIUM NOSTOC COMMUNE
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DOI：
10.1074/jbc.270.15.8536
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发表时间：
1995-04-14
影响因子：
4.8
通讯作者：
SCHERER, S
中科院分区：
文献类型：
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作者：
BOHM, GA;PFLEIDERER, W;SCHERER, S
水溶性UV-A/B吸收色素是由世界各地的陆生蓝藻发菜细胞分泌的。这些颜料构成了一种分子质量高达1801Da的复杂的单体混合物。两个最大吸收峰位于312和335 nm的不同发色团与不同的氨基酸和由半乳糖、葡萄糖、木糖、葡萄糖醛酸和氨基葡萄糖组成的低聚糖相连。335 nm的发色团是1，3-二氨基环己烯的衍生物，而最大吸收峰位于312 nm的发色团很可能是3-氨基环己烯-1-酮的衍生物。这些紫外线诱导物质是第一个被描述为共价连接到低聚糖上的霉孢菌素。这些色素位于发菜菌落的胞外糖鞘中，在那里它们形成了极高分子质量的络合物，并以非共价方式附着在糖鞘上。色素的浓度允许细胞衰减入射的UV-B辐射的很大一部分。
Water-soluble UV-A/B-absorbing pigments are secreted by cells of the cosmopolitan terrestrial cyanobacterium Nostoc commune. The pigments constitute a complex mixture of monomers with molecular masses of up to 1801 Da. Two different chromophores with absorption maxima at 312 and 335 nm are linked to different amino acids and to oligosaccharides consisting of galactose, glucose, xylose, glucuronic acid, and glucosamine. The 335 nm chromophore is a 1,3-diaminocyclohexen derivative, while the chromophore with an absorption maximum at 312 nm is most likely a 3-aminocyclohexen-1-one derivative. These UV-inducible substances are the first mycosporines to be described covalently linked to oligosaccharides. The pigments are located in the extracellular glycan sheath of Nostoc colonies, where they form complexes of extremely high molecular mass that are attached noncovalently to the glycan sheath. Pigments occur in concentrations that permit the cells to attenuate a significant part of incident UV-B radiation.