Balakrishnan A R, Easwaran K R
Molecular Biophysics Unit, Indian Institute of Science, Bangalore.
J Biomol Struct Dyn. 1993 Oct;11(2):417-28. doi: 10.1080/07391102.1993.10508735.
Detailed studies on the solution conformation of polyene antibiotic, filipin III using circular dichroism (CD) and proton nuclear magnetic resonance techniques have been carried out. In dimethyl sulfoxide (DMSO), filipin III exhibits concentration dependent aggregation-monomeric at lower and oligomeric at higher concentrations of the antibiotic. At concentrations used for 1H NMR studies (6 x 10(-3)M) the molecule coexists as monomeric and oligomeric species. However, titration experiments indicated that, in a mixed solvent system of DMSO:methanol (2:3 v/v) the antibiotic exists only as a monomer. Complete 1H NMR assignments and the conformation of the monomer filipin III have been determined by the combined use of DQFCOSY and ROESY experiments in DMSO:methanol solvent system.
已使用圆二色性（CD）和质子核磁共振技术对多烯抗生素制霉菌素III的溶液构象进行了详细研究。在二甲基亚砜（DMSO）中，制霉菌素III在较低浓度下呈现浓度依赖性的聚集 - 单体状态，在较高浓度下则为寡聚体。在用于1H NMR研究的浓度（6×10⁻³M）下，该分子以单体和寡聚体形式共存。然而，滴定实验表明，在DMSO：甲醇（2：3 v/v）的混合溶剂体系中，抗生素仅以单体形式存在。通过在DMSO：甲醇溶剂体系中联合使用双量子滤波相关谱（DQFCOSY）和旋转 Overhauser 效应谱（ROESY）实验，已确定了单体制霉菌素III的完整1H NMR归属和构象。
