Spectral snapshots of bacterial cell-wall composition and the influence of antibiotics by whole-cell NMR.
Spectral snapshots of bacterial cell-wall composition and the influence of antibiotics by whole-cell NMR.
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DOI：
10.1016/j.bpj.2015.01.037
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发表时间：
2015-03
影响因子：
3.4
通讯作者：
R. Nygaard;J. Romaniuk;D. Rice;L. Cegelski
中科院分区：
文献类型：
--
作者：
R. Nygaard;J. Romaniuk;D. Rice;L. Cegelski
革兰氏阳性菌用厚的细胞壁包围自己，这对细胞生存至关重要，也是抗生素的主要目标。量化细胞壁组成的变化对于评估药物作用模式至关重要，对于现在对多种抗生素具有耐药性的人类病原体（如金黄色葡萄球菌）尤其重要。大分子和全细胞核磁共振光谱使我们能够观察到完整的碳和氮池在金黄色葡萄球菌细胞壁和完整的全细胞。我们发现，一维13 C和15 N核磁共振光谱，以及基于偶极耦合的光谱选择和二维自旋扩散测量，揭示了完整细胞和细胞壁之间巨大的组成差异，并允许识别全细胞中的细胞壁特征。细胞样本。此外，全细胞NMR方法表现出的敏感性，以检测不同的成分变化，由于治疗与抗生素磷霉素（细胞壁生物合成抑制剂）和氯霉素（蛋白质合成抑制剂）。用磷霉素处理的全细胞表现出肽聚糖贡献减少，而用氯霉素处理的全细胞含有较高百分比的肽聚糖，因为细胞质蛋白质含量减少。因此，一般抗生素的作用模式可以通过分析完整全细胞中的总碳库来鉴定。
Gram-positive bacteria surround themselves with a thick cell wall that is essential to cell survival and is a major target of antibiotics. Quantifying alterations in cell-wall composition are crucial to evaluating drug modes of action, particularly important for human pathogens that are now resistant to multiple antibiotics such asStaphylococcus aureus. Macromolecular and whole-cell NMR spectroscopy allowed us to observe the full panel of carbon and nitrogen pools inS. aureuscell walls and intact whole cells. We discovered that one-dimensional13C and15N NMR spectra, together with spectroscopic selections based on dipolar couplings as well as two-dimensional spin-diffusion measurements, revealed the dramatic compositional differences between intact cells and cell walls and allowed the identification of cell-wall signatures in whole-cell samples. Furthermore, the whole-cell NMR approach exhibited the sensitivity to detect distinct compositional changes due to treatment with the antibiotics fosfomycin (a cell-wall biosynthesis inhibitor) and chloramphenicol (a protein synthesis inhibitor). Whole cells treated with fosfomycin exhibited decreased peptidoglycan contributions while those treated with chloramphenicol contained a higher percentage of peptidoglycan as cytoplasmic protein content was reduced. Thus, general antibiotic modes of action can be identified by profiling the total carbon pools in intact whole cells.