Recognition of human milk oligosaccharides by bacterial exotoxins
Recognition of human milk oligosaccharides by bacterial exotoxins
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DOI：
10.1093/glycob/cwv025
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发表时间：
2015-08-01
期刊：
影响因子：
4.3
通讯作者：
Klassen, John S.
中科院分区：
文献类型：
--
作者：
El-Hawiet, Amr;Kitova, Elena N.;Klassen, John S.
首次定量了母乳中发现的最丰富的寡糖与四种细菌外毒素（来自霍乱弧菌和致病性大肠杆菌）的亲和力。使用直接电喷雾电离质谱测定法在 25 摄氏度和 pH 7 条件下测量与志贺毒素 2 型全毒素 (Stx2) 以及霍乱毒素、不耐热毒素和志贺毒素 1 型 B 亚基同五聚体（CTB5、HLTB5 和 Stx1B(5)）结合的 20 种母乳寡糖 (HMO) 文库的关联常数 (K-a)。值得注意的是，所有四种细菌毒素均与大多数测试的 HMO 结合，其中 5 种 HMO（2'-岩藻糖基乳糖、乳-N-四糖、乳-N-岩藻五糖 I、乳-N-岩藻五糖 II 和乳-N-岩藻五糖 III）是所有四种毒素的配体。据报道，这五种 HMO 还可以与其他细菌毒素（例如艰难梭菌的毒素 A 和毒素 B）结合。在所有情况下，HMO 亲和力（表观 K-a）都相对适中（
The affinities of the most abundant oligosaccharides found in human milk for four bacterial exotoxins (from Vibrio cholerae and pathogenic Escherichia coli) were quantified for the first time. Association constants (K-a)for a library of 20 human milk oligosaccharides (HMOs) binding to Shiga toxin type 2 holotoxin (Stx2) and the B subunit homopentamers of cholera toxin, heat-labile toxin and Shiga toxin type 1 (CTB5, HLTB5 and Stx1B(5)) were measured at 25 degrees C and pH 7 using the direct electrospray ionization mass spectrometry assay. Notably, all four bacterial toxins bind to a majority of the HMOs tested and five of the HMOs (2'-fucosyllactose, lacto-N-tetraose, lacto-N-fucopentaose I, lacto-N-fucopentaose II and lacto-N-fucopentaose III) are ligands for all four toxins. These five HMOs are also reported to bind to other bacterial toxins (e.g. toxin A and toxin B of Clostridium difficile). In all cases, the HMO affinities (apparent K-a) are relatively modest (