Zhu K, Wei Y M, Li J X, Chen K M, Zheng Z, Yan Y B
Department of Biochemistry, Second Military Medical University, Shanghai.
Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi. 1994;12(1):20-2.
In this study p-aminophenyl-2-acetamido-2-deoxy-beta-D-glucopyranoside was bound covalently to bovine serum albumin (BSA) to form neoglycoprotein (GlcNAc-BSA). The antigenicity of BSA and the pyranose structure of the sugar was preserved. By using the neoglycoprotein antibody against BSA and staphylococcal protein A-gold (SPA-gold), Plasmodium falciparum FCC-1/HN merozoites were immunolabeled. The labelled sample was observed under transmission electron microscope (TEM). The TEM pictures showed that colloidal gold pellets were distributed all over the merozoite surface. This is the first report on the direct experimental evidence of molecular recognition between GlcNAc-BSA (or GlcNAc) and Plasmodium falciparum merozoites. But free GlcNAc or even GlcN can inhibit the immunolabeleation. The results support the hypothesis that, besides N-acetylneuraminic acid, GlcNAc is involved as another recognized site on GPA for Plasmodium falciparum. Thus we further confirmed that N-acetyl of GlcNAc is not necessary for the recognition.
在本研究中，对氨基苯基-2-乙酰氨基-2-脱氧-β-D-吡喃葡萄糖苷与牛血清白蛋白（BSA）共价结合形成新糖蛋白（GlcNAc-BSA）。BSA的抗原性和糖的吡喃糖结构得以保留。利用抗BSA的新糖蛋白抗体和葡萄球菌蛋白A-金（SPA-金），对恶性疟原虫FCC-1/HN裂殖子进行免疫标记。将标记后的样品置于透射电子显微镜（TEM）下观察。TEM照片显示，胶体金颗粒分布于整个裂殖子表面。这是关于GlcNAc-BSA（或GlcNAc）与恶性疟原虫裂殖子之间分子识别直接实验证据的首次报道。但游离的GlcNAc甚至GlcN均可抑制免疫标记。这些结果支持以下假说：除N-乙酰神经氨酸外，GlcNAc作为恶性疟原虫在糖蛋白A（GPA）上的另一个识别位点参与其中。因此，我们进一步证实GlcNAc的N-乙酰基对于识别并非必需。
