EFFECT OF STREPTOLYSIN O ON ERYTHROCYTE-MEMBRANES, LIPOSOMES, AND LIPID DISPERSIONS - PROTEIN CHOLESTEROL INTERACTION
EFFECT OF STREPTOLYSIN O ON ERYTHROCYTE-MEMBRANES, LIPOSOMES, AND LIPID DISPERSIONS - PROTEIN CHOLESTEROL INTERACTION
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DOI：
10.1083/jcb.67.1.160
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发表时间：
1975-01-01
影响因子：
7.8
通讯作者：
SCHLEGEL, R
中科院分区：
文献类型：
--
作者：
DUNCAN, JL;SCHLEGEL, R
考察了细菌溶细胞素O(SLO)对兔红细胞膜、脂质体和脂质分散体的影响。SLO对红细胞膜的主要蛋白质或脂类没有明显的影响。而经SLO处理后的红细胞膜在电子显微镜下可见环状结构和“C”字形结构。环具有电子致密中心，直径24 nm，结构总直径为38 nm。当红细胞膜在加入毒素前用戊二醛和OsO4固定时，也会形成环。相反，当毒素在0℃处理红细胞时，没有出现环，这表明SLO在膜上的吸附不足以形成环，因为已知毒素在那个温度下与红细胞结合。SLO处理后，卵磷脂-胆固醇-二乙基磷酸脂质体上出现了环状结构，但没有捕获的内部标志物K2CrO4或葡萄糖的释放。胆固醇在形成环和C‘s中的关键作用被证明是因为这些结构存在于毒素处理的胆固醇分散体中，而不是存在于卵磷脂-二乙基磷酸盐分散体中，也不只存在于SLO制剂中。发现在加入SLO之前用洋地黄素处理过的膜或胆固醇分散体中不存在环，这也表明了胆固醇的重要性。虽然环看起来不像是膜上的孔，但提出了一个模型，认为胆固醇分子在环和C结构的形成过程中被隔离，这一过程在SLO诱导的溶血中发挥了作用。这种毒素是一种分子量约为60,000道尔顿的蛋白质，是一组被称为不稳定氧毒素(3)的细胞溶解毒素的特征。这组毒素是由几种不同的革兰氏阳性菌产生的
The effect of the bacterial cytolytic toxin, streptolysin O (SLO), on rabbit erythrocyte membranes, liposomes, and lipid dispersions was examined. SLO produced no gross alterations in the major erythrocyte membrane proteins or lipids. However, when erythrocytes were treated with SLO and examined by electron microscopy, rings and" C"-shaped structures were observed in the cell membrane. The rings had an electron-dense center, 24 nm in diameter, and the overall diameter of the structure was 38 nm. Ring formation also occurred when erythrocyte membranes were fixed with glutaraldehyde and OsO4 before the addition of toxin. In contrast, rings were not seen when erythrocytes were treated with toxin at 0~ indicating that adsorption of SLO to the membrane is not sufficient for ring formation since toxin is known to bind to erythrocytes at that temperature. The ring structures were present on lecithin-cholesterol-dicetylphosphate liposomes after SLO treatment, but there was no release of the trapped, internal markers, K2CrO4 or glucose. The crucial role of cholesterol in the formation of rings and C's was demonstrated by the fact that these structures were present in toxin-treated cholesterol dispersions, but not in lecithin-dicetylphosphate dispersions nor in the SLO preparations alone. The importance of cholesterol was also shown by the finding that no rings were present in membranes or cholesterol dispersions which had been treated with digitonin before SLO was added. Although the rings do not appear to be" holes" in the membrane, a model is proposed which suggests that cholesterol molecules are sequestered during ring and C-structure formation, and that this process plays a role in SLO-induced hemolysis.Streptolysin O (SLO) is a bacterial toxin produced by virtually all strains of Streptococcus pyogenes. The toxin is a protein with a molecular weight of approximately 60,000 daltons, and is characteristic of a group of cytolytic toxins known as the oxygen-labile toxins (3). The toxins in this group are produced by several different gram-positive