Supramolecular structural analysis of the pore forming protein

为了阐明海生无脊椎动物棘瓜（Cucumaria echinata）中溶血凝集素的成孔寡聚结构，采用小角x射线散射和圆二色分析（CD）方法进行了研究。CEL-III在人工低聚溶液中形成25聚体，但在洗涤剂存在下解离成六聚体。这表明六聚体是溶血活性的最小单位。Kratky图显示，在没有Ca^（2+）或乳糖或两者同时存在的情况下，CEL-III的三级结构被破坏，光谱与随机线圈结构相似。CD谱分析表明，在相同条件下，其二级结构与单体CEL-III基本一致。这些结果表明，在低聚作用下，CEL-III的三级结构几乎被破坏，但仍具有与单体CEL-III相同的二级结构。

To elucidate the pore forming oligomeric structure of the hemolytic lectin derived from sea invertebrate Cucumaria echinata, small-angle x-ray scattering and circular dicolorism(CD) were carried out. CEL-III forms 25-mer in artificial oligomerization solution, but it dissociate into hexamer in the presence of detergent. This suggests that the hexamer is minimum unit of hemolytic activity. Kratky plot showed that the tertiary structure of CEL-III was destroyed and spectra were similar to that of the random coil structure in the absence of Ca^(2+)or lacturose or both. Whereas, CD spectra showed that the secondary structure was almost same as monomeric CEL-III under the same condition. These results suggest that the tertiary structure of CEL-III under the oligomerization was almost destroyed, but still contains same secondary structure as monomeric CEL-III.