Oligomerization and Pore Formation of a Sphingomyelin-specific Toxin, Lysenin*
Oligomerization and Pore Formation of a Sphingomyelin-specific Toxin, Lysenin*
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DOI：
10.1074/jbc.m213209200
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发表时间：
2003-06
影响因子：
4.8
通讯作者：
A. Yamaji-Hasegawa;A. Makino;T. Baba;Yukiko Senoh;H. Kimura-Suda;Satoshi Sato;N. Terada;S. Ohno;E. Kiyokawa;M. Umeda;Toshihide Kobayashi
中科院分区：
文献类型：
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作者：
A. Yamaji-Hasegawa;A. Makino;T. Baba;Yukiko Senoh;H. Kimura-Suda;Satoshi Sato;N. Terada;S. Ohno;E. Kiyokawa;M. Umeda;Toshihide Kobayashi
Lysenin 是一种源自蚯蚓 Eisenia foetida 体腔液的新型蛋白质，可特异性识别鞘磷脂并诱导细胞溶解。溶素诱导细胞裂解的机制尚未阐明。在本报告中，我们研究了赖氨酸与红细胞以及人工脂质体的相互作用。我们的结果表明，溶素结合膜并以鞘磷脂依赖性方式组装成抗 SDS 的寡聚体，导致形成流体动力学直径约为 3 nm 的孔。抗体扫描分析表明，溶素蛋白的C端区域暴露，而N端区域隐藏在分离的寡聚物复合物中。差示扫描量热法显示，溶菌素与鞘磷脂的亲水性头基和疏水性烃尾部相互作用。鞘磷脂的酰胺连接脂肪酸组成影响寡聚化但不影响结合，这表明膜流动性在寡聚化步骤中的作用。
Lysenin is a novel protein derived from coelomic fluid of the earthworm Eisenia foetida, which specifically recognizes sphingomyelin and induces cytolysis. The mechanism underlying lysenin-induced cell lysis has not been clarified. In this report we studied the interaction of lysenin with red blood cells as well as artificial liposomes. Our results showed that lysenin bound membranes and assembled to SDS-resistant oligomers in a sphingomyelin-dependent manner, leading to the formation of pores with a hydrodynamic diameter of ∼3 nm. Antibody scanning analysis suggested that the C-terminal region of lysenin was exposed, whereas the N-terminal was hidden in the isolated oligomer complex. Differential scanning calorimetry revealed that lysenin interacted with both hydrophilic head group and hydrophobic hydrocarbon tails of sphingomyelin. Oligomerization but not binding was affected by the amide-linked fatty acid composition of sphingomyelin, suggesting the role of membrane fluidity in the oligomerization step.