Mandal D K, Brewer C F
Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, New York 10461.
Biochemistry. 1992 Dec 22;31(50):12602-9. doi: 10.1021/bi00165a009.
We have previously demonstrated that the interactions between branched chain oligosaccharides and glycopeptides isolated from glycoproteins and glycolipids with specific lectins lead to the formation of homopolymeric carbohydrate-protein cross-linked complexes, even in the presence of mixtures of the carbohydrates or lectins [cf. Bhattacharyya, L., Fant, J., Lonn, H., & Brewer, C. F. (1990) Biochemistry 29, 7523-7530]. Recently, we have shown that highly ordered cross-linked lattices are formed between the tetrameric glycoprotein soybean agglutinin (SBA), which possesses a Man9 oligomannose chain per monomer, and the Glc/Man-specific plant lectin concanavalin A (Con A) [Khan, M. I., Mandal, D. K., & Brewer, C. F. (1991) Carbohydr. Res. 213, 69-77]. Using radiolabeling and quantitative precipitation techniques, we show in the present study that Con A binds and forms unique cross-linked complexes with four different glycoproteins having different numbers and types of carbohydrate chains as well as different quaternary structures. The glycoproteins include quail ovalbumin, Lotus tetragonolobus isolectin A (LTL-A), Erythrina cristagalli lectin (ECL), and Erythrina corallodendron lectin (EcorL). The results show that a preparation of quail ovalbumin containing either one Man7 or Man8 oligomannose chain per molecule forms a 1:2 cross-linked complex with tetrameric Con A, thereby demonstrating bivalency of the single carbohydrate chain(s) on the glycoprotein. Tetrameric LTL-A and dimeric ECL, which possess two xylose-containing carbohydrate chains per monomer, both form 1:2 and 1:1 cross-linked complexes (per monomer) of glycoprotein to lectin, depending on their relative ratios in solution. However, dimeric EcorL, which has the same carbohydrate structure and number of chains as ECL, forms only a 1:2 cross-linked complex with tetrameric Con A.(ABSTRACT TRUNCATED AT 250 WORDS)
我们之前已经证明，支链寡糖与从糖蛋白和糖脂中分离出的糖肽与特定凝集素之间的相互作用会导致形成同聚碳水化合物 - 蛋白质交联复合物，即使存在碳水化合物或凝集素的混合物[参见Bhattacharyya, L., Fant, J., Lonn, H., & Brewer, C. F. (1990) Biochemistry 29, 7523 - 7530]。最近，我们表明，在每个单体具有一个Man9寡甘露糖链的四聚体糖蛋白大豆凝集素（SBA）和Glc/Man特异性植物凝集素伴刀豆球蛋白A（Con A）之间形成了高度有序的交联晶格[Khan, M. I., Mandal, D. K., & Brewer, C. F. (1991) Carbohydr. Res. 213, 69 - 77]。在本研究中，我们使用放射性标记和定量沉淀技术表明，Con A与四种不同的糖蛋白结合并形成独特的交联复合物，这些糖蛋白具有不同数量和类型的碳水化合物链以及不同的四级结构。这些糖蛋白包括鹌鹑卵清蛋白、百脉根异凝集素A（LTL - A）、刺桐凝集素（ECL）和珊瑚刺桐凝集素（EcorL）。结果表明，每分子含有一个Man7或Man8寡甘露糖链的鹌鹑卵清蛋白制剂与四聚体Con A形成1:2交联复合物，从而证明了糖蛋白上单个碳水化合物链的二价性。每个单体具有两条含木糖碳水化合物链的四聚体LTL - A和二聚体ECL，根据它们在溶液中的相对比例，均形成糖蛋白与凝集素的1:2和1:1交联复合物（每个单体）。然而，具有与ECL相同碳水化合物结构和链数的二聚体EcorL仅与四聚体Con A形成1:2交联复合物。（摘要截短于250字）
