Sato T, Serizawa T, Ohtake F, Nakamura M, Terabayashi T, Kawanishi Y, Okahata Y
Department of Biomolecular Engineering, Tokyo Institute of Technology, Yokohama, Japan.
Biochim Biophys Acta. 1998 Mar 12;1380(1):82-92. doi: 10.1016/s0304-4165(97)00133-5.
Monosialogangliosides (GM1, GM2, GM3 and GM4) were reconstituted in lipid monolayers at the air-water interface. The binding amounts and the initial binding rates of wheat germ agglutinin (WGA) to the monosialoganglioside monolayers were quantitatively studied by use of a quartz-crystal microbalance (QCM). A QCM was horizontally attached to the monolayer from the air phase, and the binding behavior (mass increase) was followed by the frequency decrease of the QCM. WGA binding affinities for the ganglioside monolayers were influenced by hydrophilic head groups of lipid matrices, densities of gangliosides, and sequences of oligosaccharide in gangliosides. Binding of WGA to the gangliosides reconstituted in a phosphatidylcholine (sphingomyelin and distearoylphosphatidylcholine) matrix was strongly suppressed, but not in a neutral glycolipids (GlcCer, GalCer, and LacCer), dipalmitoylphosphatidylethanolamine, and dipalmitoylphosphatidylethanolamine matrix. WGA showed high affinity for monolayers containing 20 mol% gangliosides, but only low affinity for 100% ganglioside monolayers. WGA preferably binds to gangliosides in the following sequence: GM3 > GM4 >> GM2 = GM1. No affinities of WGA for GM2 and GM1 were observed. The combined techniques of monolayer and QCM have the advantages of investigating recognition properties of gangliosides.
单唾液酸神经节苷脂（GM1、GM2、GM3和GM4）在气-水界面的脂质单分子层中进行了重构。利用石英晶体微天平（QCM）定量研究了麦胚凝集素（WGA）与单唾液酸神经节苷脂单分子层的结合量和初始结合速率。将QCM从气相水平附着到单分子层上，通过QCM频率的降低跟踪结合行为（质量增加）。WGA对神经节苷脂单分子层的结合亲和力受脂质基质的亲水头部基团、神经节苷脂的密度以及神经节苷脂中寡糖序列的影响。WGA与重构于磷脂酰胆碱（鞘磷脂和二硬脂酰磷脂酰胆碱）基质中的神经节苷脂的结合受到强烈抑制，但在中性糖脂（葡萄糖神经酰胺、半乳糖神经酰胺和乳糖神经酰胺）、二棕榈酰磷脂酰乙醇胺和二棕榈酰磷脂酰乙醇胺基质中则不受抑制。WGA对含有20 mol%神经节苷脂的单分子层表现出高亲和力，但对100%神经节苷脂单分子层仅表现出低亲和力。WGA优先按照以下顺序与神经节苷脂结合：GM3 > GM4 >> GM2 = GM1。未观察到WGA对GM2和GM1的亲和力。单分子层和QCM的联合技术在研究神经节苷脂的识别特性方面具有优势。
