Structural basis for the unusual carbohydrate-binding specificity of jacalin towards galactose and mannose
Structural basis for the unusual carbohydrate-binding specificity of jacalin towards galactose and mannose
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DOI：
10.1042/bj3640173
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发表时间：
2002-05-15
影响因子：
4.1
通讯作者：
Rougé, P
中科院分区：
文献类型：
--
作者：
Bourne, Y;Astoul, CH;Rougé, P
有证据表明，菠萝蜜的种子凝集素JAXALIN不仅针对T抗原二糖Galbeta1，3GalNAc，乳糖和半乳糖，还针对甘露糖和低聚甘露糖苷。基于表面等离子体共振测量的生化分析，结合2埃分辨率的X-射线结晶学测定，清楚地证明了JAXALIN完全能够与甘露糖结合。除甘露糖外，黄花苷还可与葡萄糖、N-乙酰神经氨酸和N-乙酰胞壁酸相互作用。结构分析表明，相对较大的碳水化合物结合部位使JAX能够容纳具有不同羟基构象的单糖，并提供了明确的证据，证明JAX的β-棱柱结构是一种足够灵活的结构支架，可以赋予单个凝集素不同的碳水化合物结合特性。
Evidence is presented that the specificity of jacalin, the seed lectin from jack fruit (Artocarpus integrifolia), is not directed exclusively against the T-antigen disaccharide Galbeta1, 3GalNAc, lactose and galactose, but also against mannose and oligomannosides. Biochemical analyses based on surface-plasmon-resonance measurements, combined with the X-ray-crystallographic determination of the structure of a jacalin alpha-methyl-mannose complex at 2 Angstrom resolution, demonstrated clearly that jacalin is fully capable of binding mannose. Besides mannose, jacalin also interacts readily with glucose, N-acetylneuraminic acid and N-acetylmuramic acid. Structural analyses demonstrated that the relatively large size of the carbohydrate-binding site enables jacalin to accommodate monosaccharides with different hydroxyl conformations and provided unambiguous evidence that the beta-prism structure of jacalin is a sufficiently flexible structural scaffold to confer different carbohydrate-binding specificities to a single lectin.