Lectin-receptor interactions in liposomes. II. Interaction of wheat germ agglutinin with phosphatidylcholine liposomes containing incorporated monosialoganglioside.
Lectin-receptor interactions in liposomes. II. Interaction of wheat germ agglutinin with phosphatidylcholine liposomes containing incorporated monosialoganglioside.
复制标题
脂质体中的凝集素-受体相互作用。
DOI：
10.1016/0005-2736(76)90037-7
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发表时间：
1976
期刊：
影响因子：
--
通讯作者：
T. Polefka
中科院分区：
文献类型：
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作者：
W. R. Redwood;T. Polefka
掺入磷脂脂质体中的牛脑神经节苷脂提供了麦芽凝集素的受体。将纯化的单唾液酸神经节苷脂与鸡蛋磷脂酰胆碱混合，生成单层脂质体。添加麦芽凝集素诱导脂质体融合，凝胶过滤分析显示凝集素掺入融合的脂质体中。通过跟踪190°光散射的变化来研究融合过程。发现增加脂质体中单唾液酸神经节苷脂的比例可以增加凝集素诱导的脂质体融合的程度和反应速率。低于大约阈值。 5 mol%，该过程极其缓慢。添加半抗原抑制剂 N-乙酰基-d-葡萄糖胺 (1 mM) 可以防止光散射的增加。在凝集素之后添加抑制剂，由于未融合的囊泡聚集体的解离导致光散射部分减少。电镜检查显示含神经节苷脂的脂质体为囊泡，直径为244±25 Å (SD)。添加麦芽凝集素后，囊泡似乎融合形成更大的囊泡，对应于初始囊泡的二聚体和三聚体。对多种单糖的抑制研究表明，神经节苷脂中存在的唾液酸部分充当凝集素受体位点。这通过麦芽凝集素不与含有脱唾液酸神经节苷脂的磷脂酰胆碱囊泡相互作用的观察得到证实。
Bovine brain gangliosides incorporated into phospholipid liposomes provide receptors for wheat germ agglutinin. Purified monosialogangliosides were mixed with egg phosphatidylcholine, and unilamellar liposomes were generated. Addition of wheat germ agglutinin induced the liposomes to fuse, and gel filtration analysis revealed that the lectin was incorporated into the fused liposomes. The fusion process was studied by following the changes in the 190° light scattering. Increasing the proportion of the monosialoganglioside in the liposomes was found to increase both the extent of the lectin-induced liposome fusion and the rate of the reaction; below a threshold of approx. 5 mol%, the process was extremely slow. The increase in light scattering could be prevented by the addition of the hapten inhibitor, N-acetyl-d-glucosamine (1 mM). Addition of the inhibitor, subsequent to the lectin, caused a partial decrease in light scattering due to the dissociation of unfused vesicle aggregates. Electron microscopic examination revealed that the ganglioside-containing liposomes were vesicles, 244±25 Å (SD) in diameter. Upon addition of wheat germ agglutinin, the vesicles appeared to fuse to form larger vesicles, corresponding to dimers and trimers of the initial vesicles. Inhibition studies with a variety of monosaccharides indicated that the sialic acid moieties present in the gangliosides acted as the lectin-receptor sites. This was confirmed by the observation that wheat germ agglutinin did not interact with phosphatidylcholine vesicles containing desialyated ganglioside.