LOCATION AND ROLE OF STEROL AT NYSTATIN-BINDING SITES
LOCATION AND ROLE OF STEROL AT NYSTATIN-BINDING SITES
复制标题
甾醇在制霉菌素结合位点的位置和作用
作者：
J. Lampen;P. Arnow;Z. Borowska;A. Laskin
Lampen，J. O.（罗格斯大学，州立大学，新玩法，新泽西州），Peter M. Arnow，Zofia Borowska，and艾伦I.拉斯金甾醇在制霉菌素结合位点的位置和作用。J. Bacteriol. 84：1152-1160。1962.-多烯抗真菌抗生素制霉菌素和N-乙酰念珠菌素在0 ℃下被分离的细胞壁和衍生的多糖或被来自酿酒酵母菌株LK 2G 12的原生质体膜迅速结合。这些结合位点在完整细胞中是相对难以接近或不反应的，因为原生质体、对数期细胞或静止期细胞对多烯的摄取是缓慢的，尤其是在0 ℃时。膜的结合似乎是细胞损伤的关键事件;因此，细胞壁摄取制霉菌素实际上可能是保护性的。所有细胞形式的结合显示出很小的可逆性。结合的放射性制霉菌素或N-乙酰（1-C14）念珠菌素没有被取代的对数期酵母细胞与大量过量的未标记的多烯孵育过程中。制霉菌素的多烯部分饱和形成全氢化合物，几乎完全消除了该分子对酵母细胞的亲和力。基本上所有被原生质体结合的多烯都存在于膜上。用甾醇络合剂毛地黄皂苷处理原生质体可将其除去。各种证据表明，膜上的结合位点含有甾醇。(The膜甾醇主要是未酯化的麦角甾醇。这一假说与某些外源甾醇与多烯复合并阻止它们对真菌的结合和生长抑制作用的能力是一致的。壁结构的结合甾醇也可能参与多烯结合，尽管不能排除壁多糖的可能功能。细菌中似乎不存在这种特异性结合结构，因为制霉菌素甚至不被加热或苯处理的细菌或细菌原生质体摄取。应该注意的是，对多烯抗生素不敏感的细菌通常仅含有痕量的甾醇（如果有的话）。大量甾醇存在于真菌、藻类、某些原生动物和动物细胞中，所有这些都在某种程度上敏感。
Lampen, J. O. (Rutgers, The State University, New Brunswick, N.J.), Peter M. Arnow, Zofia Borowska, and Allen I. Laskin. Location and role of sterol at nystatin-binding sites. J. Bacteriol. 84:1152–1160. 1962.—The polyene antifungal antibiotics nystatin and N-acetylcandidin were bound rapidly at 0 C by isolated cell walls and derived polysaccharides or by protoplast membranes from Saccharomyces cerevisiae strain LK2G12. These binding sites were relatively inaccessible or unreactive in the intact cell, since polyene uptake by protoplasts, log-phase cells, or stationary-phase cells was slow, especially at 0 C. Binding by the membrane appears to be the critical event in cell damage; thus, uptake of nystatin by the cell wall may actually be protective. Binding by all cell forms showed little reversibility. Bound radioactive nystatin or N-acetyl (1-C14) candidin was not displaced during incubation of log-phase yeast cells with a large excess of unlabeled polyene. Saturation of the polyenic moiety of nystatin to form the perhydro compound eliminated almost completely the affinity of the molecule for the yeast cell. Essentially all of the polyene bound by protoplasts was present on the membrane. It was removed by treatment of the protoplasts with the sterol-complexing agent digitonin. A variety of evidence is offered that the binding site on the membrane contains a sterol. (The membrane sterol was mostly unesterified ergosterol.) This hypothesis is consistent with the ability of certain exogenous sterols to complex with polyenes and prevent their binding and growth-inhibiting action for fungi. The bound sterol of the wall structure may also participate in polyene binding, although a possible function of the wall polysaccharides cannot be excluded. The specific binding structure(s) appears to be absent from bacteria, since nystatin was not taken up even by heated or benzene-treated bacteria or by bacterial protoplasts. It should be noted that bacteria, which are insensitive to the polyene antibiotics, generally contain only traces of sterol, if any. Considerable quantities of sterol are present in fungi, algae, certain protozoa, and animal cells, all of which are sensitive in some degree.