Study on the structure of marine invertebrate lectins and their cell membrane-damaging action

碳氢化合物结合蛋白（lectins）的结构和功能来自海洋黄瓜（Cucumaria echinata）和其他海洋invertebrates were investigated。Among four Ca D12+ D1-dependent lectins from C. echinata，一种半乳糖/N-乙酰半乳糖胺-特定课程， CEL-III，展示了通过在细胞膜中形成可渗透细胞的人体和兔细胞的强有力的血细胞活性。订购以识别CEL-III受体，膜脂质从人类细胞中净化，并对CEL-III受体的能力进行了评估。作为一个结果，糖基脂含有β-半乳糖或N-乙酰半乳糖胺的非减少结果显示出高亲和力，作为CEL-III的有效受体能力。更进一步，这也被认为不仅取决于CEL-III的受体能力，而且也取决于碳水化合物链的结构或长度。关于另一方，化学修饰研究揭示了CEL-III的氨基和羧基组被纳入了Hemolytic Mechanism。对氨基组进行了适当的修改，仅对血红素活性进行了修改，对羧基组进行了降解，对CEL-III的血红素活性和血红素活性进行了两次降解。以下建议是，一些碳基组被纳入CEL-III的两个碳基结合站点之一。作为一种这样的Hemolytic Lectin的模型，一种新型的蛋白质结合了Lectin和amphiphilic α-helpeptides也是准备好的。由于他们展示了血细胞活性，依赖于碳水化合物结合的自然，这些聚合物被认为是与细胞膜在结合到表面碳水化合物链后进行交互的。

Structure and function of the carbohydrate-binding proteins (lectins) from a sea cucumber (Cucumaria echinata) and other marine invertebrates were investigated. Among four CaィイD12+ィエD1-dependent lectins from C. echinata, a galactose/N-acetylgalactosamine-specific lectin, CEL-III, exhibited strong hemolytic activity toward human and rabbit erythrocytes by forming ion-permeable pores in the cell membrane. In order to identify CEL-III receptor, membrane lipids were purified from human erythrocytes, and were assessed for their CEL-III receptor ability. As a result, glycolipids containing β-galactose or N-acetylgalactosamine at their nonreducing ends showed high affinity as well as effective receptor ability for CEL-III. Furthermore, it was also suggested that the receptor ability depends not only on the affinity for CEL-III, but also on the structure or length of the carbohydrate chains. On the other hand, chemical modification studies revealed that amino and carboxyl groups of CEL-III are involved in the hemolytic mechanism. Although modification of amino groups markedly reduced only hemolytic activity, modification of carboxyl groups led to decrease in both hemolytic and hemagglutinating activity of CEL-III. This suggests that some carboxyl groups are involved in one of two carbohydrate-binding sites of CEL-III. As a model of such a hemolytic lectin, novel protein conjugates consisting of lectins and amphiphilic α-helical peptides were also prepared. Since they exhibited hemolytic activity, depending on the carbohydrate-binding nature, these conjugates were suggested to interact with cell membrane after binding to the surface carbohydrate chains.