Comparative cross-linking activities of lactose-specific plant and animal lectins and a natural lactose-binding immunoglobulin G fraction from human serum with asialofetuin
Comparative cross-linking activities of lactose-specific plant and animal lectins and a natural lactose-binding immunoglobulin G fraction from human serum with asialofetuin
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DOI：
10.1093/glycob/6.8.843
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发表时间：
1996-12-01
期刊：
影响因子：
4.3
通讯作者：
Brewer, CF
中科院分区：
文献类型：
--
作者：
Gupta, D;Kaltner, H;Brewer, CF
植物和动物凝集素结合和交联某些多天线寡糖，糖肽和糖蛋白，这可以导致形成均匀的交联复合物，其化学数量可能不同，这取决于所涉及的糖受体的性质。作为一个精确定义的配体，我们使用了牛asialofetuin (ASF)，一种糖蛋白，具有三个天冬酰胺连接的三天线复合碳水化合物链，末端有LacNAc残基。在本研究中，我们比较了两种lac特异性植物凝集素的碳水化合物交联特性，一种是动物凝集素，另一种是来自人血清的自然存在的lac结合多克隆免疫球蛋白G亚片段。定量沉淀研究表明，lac特异性植物凝集素、Viscum album凝集素和Ricinus communis凝集素，以及来自鸡肝脏的lac特异性16 kDa二聚体凝集素，在ASF浓度较低时，与植物凝集素和鸡凝集素均形成1:9的ASF/凝集素（单体）复合物，而随着ASF浓度的增加，与凝集素形成1:3的ASF/凝集素（单体）复合物，无论其来源或大小如何。这些研究表明，lac特异性植物和动物凝集素以及与lac结合的免疫球蛋白亚片段与ASF形成特异性的化学计量交联复合物，这些结果在多价凝集素和抗体的结构-功能特性方面进行了讨论。
Plant and animal lectins bind and cross-link certain multiantennary oligosaccharides, glycopeptides, and glycoproteins, This can lead to the formation of homogeneous crosslinked complexes, which may differ in their stoichiometry depending on the nature of the sugar receptor involved, As a precisely defined ligand, we have employed bovine asialofetuin (ASF), a glycoprotein that possesses three asparagine-linked triantennary complex carbohydrate chains with terminal LacNAc residues, In the present study, we have compared the carbohydrate cross-linking properties of two Lac-specific plant lectins, an animal lectin and a naturally occurring Lac-binding polyclonal immunoglobulin G subfraction from human serum with the ligand, Quantitative precipitation studies of the Lac-specific plant lectins, Viscum album agglutinin and Ricinus communis agglutinin, and the Lac-specific 16 kDa dimeric galectin from chicken liver demonstrate that these lectins form specific, stoichiometric cross-linked complexes with ASF, At low concentrations of ASF, 1:9 ASF/lectin (monomer) complexes formed with both plant lectins and the chicken lectin, With increasing concentrations of ASF, 1:3 ASF/lectin (monomer) complexes formed with the lectins irrespective of their source or size, The naturally occurring polyclonal antibodies, however, revealed a different cross-linking behavior. They show the formation of 1:3 ASF/antibody (per Fab moiety) cross-linked complexes at all concentrations of ASF, These studies demonstrate that Lac-specific plant and animal lectins as well as the Lac-binding immunoglobulin subfraction form specific stoichiometric cross-linked complexes with ASF, These results are discussed in terms of the structure-function properties of multivalent lectins and antibodies.