Visualization of mycobacterial membrane dynamics in live cells.
Visualization of mycobacterial membrane dynamics in live cells.
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DOI：
10.1021/jacs.6b12541
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发表时间：
2017-03-08
影响因子：
15
通讯作者：
Bertozzi CR
中科院分区：
文献类型：
--
作者：
Rodriguez-Rivera FP;Zhou X;Theriot JA;Bertozzi CR
分枝杆菌具有高度不渗透的菌膜，对许多抗生素具有内在抗性。几种独特的菌膜糖脂已被分离和结构表征，但糖脂在细胞包膜内的潜在组织和动力学仍然知之甚少。我们在这里报告了一项真菌膜动力学的研究，该研究是通过能够标记活放线菌中海藻糖糖脂的海藻糖-荧光基团偶联物实现的。我们鉴定了荧光素海藻糖类似物，其代谢结合到代表性分枝杆菌、棒状杆菌、诺卡菌和红球菌物种的海藻糖真菌酸盐中。利用这些探针，我们通过延时显微镜和光漂白实验后的荧光恢复研究了标记的糖脂的流动性，发现菌丝膜流动性在不同物种之间差异很大，并且与霉菌酸结构相关。最后，我们发现用乙胺丁醇（一种结核病（TB）一线药物）治疗分枝杆菌可显著增加菌膜流动性。这些发现增强了我们对分枝杆菌包膜结构和动力学的理解，并对结核药物鸡尾酒的开发具有指导意义。
Mycobacteria are endowed with a highly impermeable mycomembrane that confers intrinsic resistance to many antibiotics. Several unique mycomembrane glycolipids have been isolated and structurally characterized, but the underlying organization and dynamics of glycolipids within the cell envelope remain poorly understood. We report here a study of mycomembrane dynamics that was enabled by trehalose–fluorophore conjugates capable of labeling trehalose glycolipids in live actinomycetes. We identified fluorescein–trehalose analogues that are metabolically incorporated into the trehalose mycolates of representative Mycobacterium, Corynebacterium, Nocardia, and Rhodococcus species. Using these probes, we studied the mobilities of labeled glycolipids by time-lapse microscopy and fluorescence recovery after photobleaching experiments and found that mycomembrane fluidity varies widely across species and correlates with mycolic acid structure. Finally, we discovered that treatment of mycobacteria with ethambutol, a front-line tuberculosis (TB) drug, significantly increases mycomembrane fluidity. These findings enhance our understanding of mycobacterial cell envelope structure and dynamics and have implications for development of TB drug cocktails.