Interactions between Vancomycin and Cell-Wall Precursor Analogs Studied by Electrospray Mass Spectrometry
Interactions between Vancomycin and Cell-Wall Precursor Analogs Studied by Electrospray Mass Spectrometry
复制标题
通过电喷雾质谱研究万古霉素和细胞壁前体类似物之间的相互作用
DOI：
10.5702/massspec.46.69
复制
发表时间：
1998
期刊：
影响因子：
--
通讯作者：
Dudley H. Williams
中科院分区：
文献类型：
--
作者：
T. Staroske;A. Heck;P. Derrick;Dudley H. Williams
糖肽抗生素万古霉素与细胞壁前体类似物N-乙酰基-D-Ala-D-Ala及其氘代对映体N-乙酰基-L-Ala-L-Ala-d3之间的非共价复合物使用电喷雾电离质谱进行探测。在溶液中，D，D-肽与抗生素强烈相互作用，而L，L-肽没有显示出可观察到的络合。使用竞争策略，从含有万古霉素、N-乙酰基-D-Ala-D-Ala和N-乙酰基-L-Ala-L-Ala-d3的溶液获得质谱。以乙腈-水作为溶剂，游离万古霉素与万古霉素复合物的比例远高于溶液相互作用的预期，并且检测到特异性D，D-肽复合物和非特异性L，L-肽复合物的比例为1.7：1。相比之下，从乙酸铵缓冲溶液喷雾，观察到的复合物的量和特异性反映了溶液相互作用（仅发现D，D-肽复合物）。因此，我们的研究结果表明，在电喷雾质谱的条件必须仔细选择，必须进行控制实验，以排除非特异性聚集作为复杂的形成的可能原因。
Non-covalent complexes between the glycopeptide antibiotic vancomycin and the cell-wall precursor analog N-acetyl-D-Ala-D-Ala, as well as its deuterated enantiomer N-acetyl-L-Ala-L-Ala-d3 were probed using electrospray ionization mass spectrometry. In solution, the D,D-peptide interacts strongly with the antibiotic, whereas the L,L-peptide shows no observable complexation. Using a competition strategy, mass spectra were obtained from solutions containing vancomycin, N-acetyl-D-Ala-D-Ala, and N-acetyl-L-Ala-L-Ala-d3. With acetonitrile-water as the solvent, the ratio of free vancomycin to vancomycin complex was much higher than expected from solution interactions and the specific D,D-peptide complex and the non-specific L,L-peptide complex were detected in a 1.7 : 1 ratio. In contrast, sprayed from an ammonium acetate buffer solution both the amount and specificity of observed complex reflected solution interactions (only D,D-peptide complex was found). Thus, our results demonstrate that in electrospray mass spectrometry the conditions must carefully be chosen and control experiments must be carried out in order to exclude non-specific aggregation as a possible cause of complex formation.