Staphylococcal α-hemolysin can form hexamers in phospholipid bilayers
Staphylococcal α-hemolysin can form hexamers in phospholipid bilayers
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DOI：
10.1006/jmbi.1997.1535
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发表时间：
1998-02-20
影响因子：
5.6
通讯作者：
Shao, ZF
中科院分区：
文献类型：
--
作者：
Czajkowsky, DM;Sheng, ST;Shao, ZF
原子力显微镜 (AFM) 用于研究在支持的磷脂双层中形成的葡萄球菌 α-溶血素 (α HL) 寡聚物的结构。与最近 X 射线晶体学演示的脱氧胆酸盐 (DOC) 胶束中形成的低聚物的七聚体化学计量相反，高分辨率未处理的 AFM 图像明确地揭示了这些磷脂双层中的六聚体。这种六聚体化学计量的独立支持是通过 AFM 图像中晶格常数的测量和凝胶电泳获得的。因此，α HL 可以形成两种不同的、能量稳定的低聚物，它们至少在化学计量上不同，而且可能在亚基结构上也不同。此外，在 AFM 图像中观察到稳定的、不完整的寡聚体，这可能与 α HL 损伤细胞的机制有关。 (C) 1998 学术出版社有限公司。
Atomic force microscopy (AFM) was used to study the structure of the staphylococcal alpha-hemolysin (alpha HL) oligomer formed in supported phospholipid bilayers. In contrast to the recent X-ray crystallographic demonstration of a heptameric stoichiometry for the oligomer formed in deoxycholate (DOC) micelles, the high-resolution unprocessed AFM images unequivocally revealed a hexamer in these phospholipid bilayers. Independent support of this hexameric stoichiometry was obtained from the measurements of the lattice constant in the AFM images and from gel electrophoresis. Therefore, alpha HL can form two different, energetically stable oligomers, which differ in at least stoichiometry but perhaps subunit structure as well. Furthermore, stable, incomplete oligomers were observed in the AFM images, which may be of relevance to the mechanism by which alpha HL damages the cell. (C) 1998 Academic Press Limited.