The Perpendicular Orientation of Amphotericin B Methyl Ester in Hydrated Lipid Bilayers Supports the Barrel-Stave Model
The Perpendicular Orientation of Amphotericin B Methyl Ester in Hydrated Lipid Bilayers Supports the Barrel-Stave Model
复制标题
两性霉素 B 甲酯在水合脂质双层中的垂直方向支持桶板模型
DOI：
10.1021/acs.biochem.9b00180
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发表时间：
2019
期刊：
影响因子：
2.9
通讯作者：
Murata Michio
中科院分区：
文献类型：
--
作者：
Yamamoto Tomoya;Umegawa Yuichi;Yamagami Masaki;Suzuki Taiga;Tsuchikawa Hiroshi;Hanashima Shinya;Matsumori Nobuaki;Murata Michio
两性霉素B （AmB）是一种针对膜固醇的膜活性天然产物，是临床上重要的抗生素。AmB的抗菌活性通常归因于其膜透性，当在脂质双分子层上形成孔时发生。本研究利用固体核磁共振（NMR）技术研究了AmB的分子取向，以更好地了解其抗真菌活性的机制。制备了核磁共振标记的AmB （AME）甲酯d3-AME及其氟化和/或13c标记衍生物。所有AmB衍生物在磷脂脂质体中表现出相似的膜破坏活性和紫外光谱，表明它们在膜上的分子组装与AmB非常相似。在水合膜中对3d -AME的固态核磁共振测量表明，AME分子的迁移率取决于浓度和温度。AME:Erg：二myristoylphosphatidycholine ratio为1:5:45时，AME被充分调动，可以观察四极耦合的运动平均。根据14β-F-AMEs的19f化学位移各向异性、2H四极分裂和13c - 19f偶极耦合的旋转平均效应，我们推断出AME的分子轴主要平行于脂质双分子层的法线。这一结果支持了桶-壁模型作为AmB在膜中的分子组装。
The clinically important antibiotic amphotericin B (AmB) is a membrane-active natural product that targets membrane sterol. The antimicrobial activity of AmB is generally attributed to its membrane permeabilization, which occurs when a pore is formed across a lipid bilayer. In this study, the molecular orientation of AmB was investigated using solid-state nuclear magnetic resonance (NMR) to better understand the mechanism of antifungal activity. The methyl ester of AmB (AME) labeled with NMR isotopes,d3-AME, and its fluorinated and/or13C-labeled derivatives were prepared. All of the AmB derivatives showed similar membrane-disrupting activities and ultraviolet spectra in phospholipid liposomes, suggesting that their molecular assemblies in membranes closely mimic those of AmB. Solid-state2H NMR measurements ofd3-AME in a hydrated membrane showed that the mobility of AME molecules depends on concentration and temperature. At a 1:5:45 AME:Erg:dimyristoylphosphatidylcholine ratio, AME became sufficiently mobilized to observe the motional averaging of quadrupole coupling. On the basis of the rotational averaging effect of19F chemical shift anisotropy,2H quadrupolar splitting, and13C–19F dipolar coupling of 14β-F-AMEs, we deduced that the molecular axis of AME is predominantly parallel to the normal of a lipid bilayer. This result supports the barrel-stave model as a molecular assembly of AmB in membranes.