Assembly of Staphylococcus aureus γ‐hemolysin into a pore‐forming ring‐shaped complex on the surface of human erythrocytes

FEBS Letters

Kamio, Yoshiyuki¹  Sugawara, Noriko¹  Tomita, Toshio¹ 

[1] Department of Applied Biological Chemistry, Faculty of Agriculture, Tohoku University, 1-1 Tsutsumi-dori Amamiya-machi, Aoba-Ku, Sendai 981, Japan

关键词: Staphylococcal γ-hemolysin;    Bi-component cytolysin;    Pore-forming toxin;    Complex formation;    Ring-shaped structure;    Hlg1;    Hlg1 (or Hγ I) component of staphylococcal γ-hemolysin;    Hlg2;    Hlg2 (or Hγ II) component of γ-hemolysin;    Tris;    tris(hydroxymethyl)aminomethane;    SDS;    sodium dodecyl sulfate;    SDS-PAGE;    SDS-polyacrylamide gel electrophoresis;   

DOI  :  10.1016/S0014-5793(97)00618-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Staphylococcal γ-hemolysin consists of Hlg1 (or Luk F) of 34 kDa and Hlg2 of 32 kDa, which cooperatively lyse human erythrocytes. Since γ-hemolysin caused swelling of human erythrocytes prior to lysis, we studied pore-forming nature of the toxin by use of polyethylene glycols as osmotic protectants and determined the functional diameter of the pore. To elucidate the molecular architecture of the membrane pore formed by γ-hemolysin, we solubilized the pore complex with 2% sodium dodecyl sulfate, separated it from erythrocyte membrane proteins by sucrose gradient ultracentrifugation, and observed the isolated complex under an electron microscope. Our data showed that Hlg1 and Hlg2 of γ-hemolysin assemble into a ring-shaped 195 kDa complex in a molar ratio of 1 : 1, which may form a membrane pore with a functional diameter of 2.1–2.4 nm.

【 授权许可】

Unknown