Nedeau P, Gruda I, Medoff G, Brajtburg J
Antimicrob Agents Chemother. 1982 Apr;21(4):545-50. doi: 10.1128/AAC.21.4.545.
Two methods, biological and spectroscopic, were used to determine the avidity of the polyene antibiotic Etruscomycin for cholesterol and ergosterol. The biological method consisted of measuring the inhibitory potency of both sterols on the Etruscomycin-induced damage to erythrocytes and fungi. The spectroscopic method consisted of recording of series of differential spectra in a number of solvents of different composition. The results obtained showed that cholesterol protected erythrocytes and candida albicans against the damaging action of Etruscomycin more efficiently than ergosterol did and that Etruscomycin-cholesterol complexes were more resistant to interruption by organic solvents than Etruscomycin-ergosterol complexes. These results and their comparison with the results obtained with other polyene antibiotics indicate that Etruscomycin resembles filipin in that it binds more avidly to cholesterol than to ergosterol. This implies that the length of the hydrophobic chain rather than the presence of the amino sugar determines sterol preference. The spectral method that we used can have general application for the quantitative measurement of complex formation between polyenes and sterols.
采用生物学和光谱学两种方法来测定多烯抗生素伊曲古霉素对胆固醇和麦角固醇的亲和力。生物学方法包括测量两种固醇对伊曲古霉素诱导的红细胞和真菌损伤的抑制效力。光谱学方法包括在多种不同组成的溶剂中记录一系列差示光谱。所得结果表明，胆固醇比麦角固醇更有效地保护红细胞和白色念珠菌免受伊曲古霉素的破坏作用，并且伊曲古霉素 - 胆固醇复合物比伊曲古霉素 - 麦角固醇复合物更能抵抗有机溶剂的干扰。这些结果以及它们与用其他多烯抗生素获得的结果的比较表明，伊曲古霉素与制霉菌素相似，即它与胆固醇的结合比与麦角固醇的结合更紧密。这意味着疏水链的长度而非氨基糖的存在决定了对固醇的偏好。我们使用的光谱学方法可普遍应用于多烯与固醇之间复合物形成的定量测定。
