Physicochemical characterization of Cajanus cajan lectin: effect of pH and metal ions on lectin carbohydrate interaction.
Physicochemical characterization of Cajanus cajan lectin: effect of pH and metal ions on lectin carbohydrate interaction.
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DOI：
10.1016/s0304-4165(99)00035-5
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发表时间：
1999-05
期刊：
影响因子：
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通讯作者：
Shama Ahmad;Rizwan Hasan Khan;Aftab Ahmad
中科院分区：
文献类型：
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作者：
Shama Ahmad;Rizwan Hasan Khan;Aftab Ahmad
用平衡透析法测定了木豆凝集素与α-d-甘露糖苷的结合常数。还试图了解金属离子的要求，并建立电离基团负责凝集素-碳水化合物的相互作用。N-端序列长达27个氨基酸残基，被发现与其他甘露糖特异性豆科植物凝集素的族Vicaceae的同源性超过80%。与伴刀豆球蛋白A和豌豆凝集素一样，它对α-甲基甘露糖也表现出很高的亲和力，在37°C时的结合常数为1.4× 104 M −1。凝集素每摩尔需要一个Ca 2+和一个Mg 2+，并且在凝集素糖相互作用期间，两个pK为3.75和8.3的可电离基团被电离。二级结构是否同样受到pH值变化和存在或不存在的金属离子的影响进行了研究，通过圆二色性研究。结果表明，在碳水化合物的结合特性的变化的木豆凝集素由于pH值的变化和金属离子的加入并不伴随着任何显着的变化，在二级结构。
The association constant of Cajanus cajan lectin for methyl α-d-mannopyranoside was studied by equilibrium dialysis method. An attempt was also made to understand the metal ion requirements and to establish that ionizable groups are responsible for lectin–carbohydrate interaction. The N-terminal sequence up to 27 amino acid residues was found to be more than 80% homologous with other mannose-specific legume lectins of the tribe Viceae. Like concanavalin A and pea lectin it also exhibits high affinity for the sugar α-methyl mannose and at 37°C the association constant was found to be 1.4×104M−1. The lectin required one Ca2+and one Mg2+per mole and during the lectin sugar interaction two ionizable groups with pK of 3.75 and 8.3 are ionized. Whether the secondary structure is similarly affected with pH changes and presence or absence of metal ion was investigated by circular dichroism studies. Results suggested that changes in carbohydrate binding properties of the Cajanus cajan lectin due to change in pH and addition of metal ions are not accompanied by any significant change in secondary structure.