Podolsky D K, Weiser M M, La Mont J T, Isselbacher K J
Proc Natl Acad Sci U S A. 1974 Mar;71(3):904-8. doi: 10.1073/pnas.71.3.904.
A correlation has been observed between concanavalin A agglutination of various cell types and the presence of surface membrane galactosyltransferase (1-O-alpha-D-Galactosyl-myo-inositol:raffinose galactosyltransferase, EC 2.4.1.67) activity. Moreover, a reduction to less than 50% of cell surface galactosyltransferase activity occurred after treatment with concanavalin A; other cell surface glycosyltransferase enzyme activities examined were unaffected by concanavalin A treatment. To confirm the participation of cell surface galactosyltransferase in concanavalin A-induced cell agglutination, the enzyme from rabbit erythrocytes was solubilized by sonication and purified by preparative polyacrylamide gel electrophoresis. It was possible to achieve a purified preparation of rabbit erythrocyte galactosyltransferase by separation on concanavalin A-Sepharose. The purified enzyme showed visible immunoprecipitation (Ouchterlony) with concanavalin A. Furthermore, human erythrocytes, which are not normally agglutinated by concanavalin A, became agglutinable by the lectin when the erythrocytes were preincubated with purified galactosyltransferase. These experiments suggest a direct and possible specific role of cell surface galactosyltransferase enzyme in the mechanism of concanavalin A agglutination of cells.
已观察到不同细胞类型的伴刀豆球蛋白A凝集作用与表面膜半乳糖基转移酶（1-O-α-D-半乳糖基-肌醇：棉子糖半乳糖基转移酶，EC 2.4.1.67）活性之间存在相关性。此外，用伴刀豆球蛋白A处理后，细胞表面半乳糖基转移酶活性降低至不到50%；所检测的其他细胞表面糖基转移酶活性不受伴刀豆球蛋白A处理的影响。为了证实细胞表面半乳糖基转移酶参与伴刀豆球蛋白A诱导的细胞凝集，通过超声处理使兔红细胞中的该酶溶解，并通过制备性聚丙烯酰胺凝胶电泳进行纯化。通过在伴刀豆球蛋白A-琼脂糖上进行分离，可以获得兔红细胞半乳糖基转移酶的纯化制剂。纯化后的酶与伴刀豆球蛋白A呈现明显的免疫沉淀反应（双向免疫扩散法）。此外，正常情况下不被伴刀豆球蛋白A凝集的人红细胞，在与纯化的半乳糖基转移酶预孵育后，可被该凝集素凝集。这些实验表明细胞表面半乳糖基转移酶在伴刀豆球蛋白A凝集细胞的机制中具有直接且可能的特异性作用。
