A new understanding of antibiotic action via solid-state NMR of cells with uniform isotopic labeling.
A new understanding of antibiotic action via solid-state NMR of cells with uniform isotopic labeling.
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通过具有统一同位素标记的细胞固态核磁共振对抗生素作用有了新的认识。
DOI：
10.1016/j.bpj.2015.02.006
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发表时间：
2015
影响因子：
3.4
通讯作者：
Weliky,DavidP
中科院分区：
文献类型：
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作者：
Weliky,DavidP
在本期的《生物物理学杂志》上，Nygaard等人。(1)描述了一种令人兴奋的新的固态核磁共振方法来探测整个细菌细胞及其细胞壁组分的组成。使用均匀的13 C和15 N标记以及魔角旋转和旋转回波双共振（REDOR）选择Gly或非Gly 13 C信号允许NMR检测许多化学官能团，包括多糖和蛋白质（2-5）。在我看来，最令人兴奋的结果是用不同抗生素培养的整个细菌细胞的未过滤13 C NMR光谱之间的显著差异，如文章中的图7所示。相对于未用抗生素处理的对照细胞，用磷霉素抗生素处理的细胞具有显著较小的多糖/蛋白质13 C信号强度比率，而用氯霉素处理的细胞具有显著较大的比率。这与已知的磷霉素抑制细胞壁合成和氯霉素抑制蛋白质合成有关。因此，这种新方法可能可以快速定量地识别新抗生素的一般作用机制。这在新抗生素的开发和比较中应该是非常有用的。(1)建立在早期的全细胞固态NMR研究Cegelski等人。(6)和Kim等人(7)更有选择性的同位素标记。阐明了奥利万星等抗生素的结合模式和作用机制。全细胞固态NMR的其他应用包括定量和分析包涵体中重组蛋白的折叠（8，9）。Nygaard等人的文章中描述的均匀标记和REDOR过滤的使用。(1)突出了固态NMR解决复杂生物材料（如细菌细胞壁）中重要问题的能力。在医学和生物技术中存在许多问题，这些方法应该提供对细菌以外的细胞类型的潜在应用的深刻见解。
In this issue of the Biophysical Journal, Nygaard et al.(1) describe an exciting new solid-state NMR approach to probe the composition of whole bacterial cells and their cell-wall fractions. Use of uniform 13C and 15N labeling as well as magic-angle spinning and rotational-echo double-resonance (REDOR) selection of either Gly or non-Gly 13C signals allows for NMR detection of many chemical functionalities including polysaccharide and protein (2–5). In my view, the most exciting result is the striking differences among unfiltered 13C NMR spectra of whole bacterial cells grown with different antibiotics, as displayed in Fig. 7 in the article. Relative to control cells that were not treated with antibiotic, cells treated with fosfomycin antibiotic have a significantly smaller ratio of polysaccharide/protein 13C signal intensities whereas cells treated with chloramphenicol have a significantly greater ratio. This correlates with the known inhibition of cell-wall synthesis by fosfomycin and protein synthesis by chloramphenicol. It is therefore likely that this new method can rapidly and quantitatively discern the general mechanism of action of a new antibiotic. This should be very useful in development and comparison of new antibiotics.The article by Nygaard et al.(1) builds on earlier whole-cell solid-state NMR studies by Cegelski et al.(6) and Kim et al.(7) with more selective isotopic labeling. The binding modes and mechanisms of action of antibiotics such as oritavancin were elucidated in this work. Other applications of whole-cell solid-state NMR include quantitation and analysis of folding of recombinant proteins in inclusion bodies (8, 9). The use of uniform labeling and REDOR filtering described in the article by Nygaard et al.(1) highlights the power of solid-state NMR to address important questions in complex biological materials such as bacterial cell walls. There are many problems in medicine and biotechnology for which these approaches should provide great insight with potential application to cell types other than bacteria.