WATER AND NONELECTROLYTE PERMEABILITY INDUCED IN THIN LIPID MEMBRANES BY POLYENE ANTIBIOTICS NYSTATIN AND AMPHOTERICIN-B
WATER AND NONELECTROLYTE PERMEABILITY INDUCED IN THIN LIPID MEMBRANES BY POLYENE ANTIBIOTICS NYSTATIN AND AMPHOTERICIN-B
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DOI：
10.1085/jgp.56.1.125
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发表时间：
1970-01-01
影响因子：
3.8
通讯作者：
HOLZ, R
中科院分区：
文献类型：
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作者：
HOLZ, R
制霉菌素和两性霉素B增加薄（<100 A）脂质膜对离子、水和非电解质的渗透性。水和非电解质渗透率随膜电导（即离子渗透率）线性增加。在未修饰的膜中，渗透渗透系数Pf等于标记的水渗透系数（Pd）w；制霉菌素或两性霉素b处理的膜，Pf/(Pd)w≈3。未经修饰的膜几乎不渗透小的亲水溶质，如尿素、乙二醇和甘油；制霉菌素或两性霉素b处理过的膜对这些溶质的渗透性根据大小而分级。这种渐变的渗透率体现在示踪剂渗透率Pd和反射系数σ中（表1）。渗透率的“切断”发生在葡萄糖大小的分子（斯托克斯-爱因斯坦半径为4 A）。我们得出结论，制霉菌素和两性霉素B在薄脂膜上形成水孔；这些孔隙的有效半径约为4a。制霉菌素或两性霉素b处理过的膜对水和小的亲水溶质的渗透性与人类红细胞膜对这些分子的渗透性有明显的相似之处。
Nystatin and amphotericin B increase the permeability of thin (<100 A) lipid membranes to ions, water, and nonelectrolytes. Water and nonelectrolyte permeability increase linearly with membrane conductance (i.e., ion permeability). In the unmodified membrane, the osmotic permeability coefficient,Pf, is equal to the tagged water permeability coefficient, (Pd)w; in the nystatin- or amphotericin B-treated membrane,Pf/(Pd)w≈ 3. The unmodified membrane is virtually impermeable to small hydrophilic solutes, such as urea, ethylene glycol, and glycerol; the nystatin- or amphotericin B-treated membrane displays a graded permeability to these solutes on the basis of size. This graded permeability is manifest both in the tracer permeabilities,Pd, and in the reflection coefficients, σ (Table I). The "cutoff" in permeability occurs with molecules about the size of glucose (Stokes-Einstein radius ≊ 4 A). We conclude that nystatin and amphotericin B create aqueous pores in thin lipid membranes; the effective radius of these pores is approximately 4 A. There is a marked similarity between the permeability of a nystatin- or amphotericin B-treated membrane to water and small hydrophilic solutes and the permeability of the human red cell membrane to these same molecules.