Department of Chemistry and Biochemistry, Baylor University , Waco, Texas 76706, United States.
Biochemistry. 2013 May 28;52(21):3651-9. doi: 10.1021/bi4005039. Epub 2013 May 14.
Staphylococcus aureus grown in the presence of an alanine-racemase inhibitor was labeled with d-[1-(13)C]alanine and l-[(15)N]alanine to characterize some details of the peptidoglycan tertiary structure. Rotational-echo double-resonance NMR of intact whole cells was used to measure internuclear distances between (13)C and (15)N of labeled amino acids incorporated in the peptidoglycan, and from those labels to (19)F of a glycopeptide drug specifically bound to the peptidoglycan. The observed (13)C-(15)N average distance of 4.1-4.4 Å between d- and l-alanines in nearest-neighbor peptide stems is consistent with a local, tightly packed, parallel-stem architecture for a repeating structural motif within the peptidoglycan of S. aureus.
在丙氨酸消旋酶抑制剂存在的情况下培养的金黄色葡萄球菌被用 d-[1-(13)C]丙氨酸和 l-[(15)N]丙氨酸进行标记,以对肽聚糖三级结构的一些细节进行特征分析。使用完整的全细胞旋转回波双共振 NMR 来测量标记在肽聚糖中的氨基酸的(13)C 和(15)N 之间的核间距离,以及从这些标记到与肽聚糖特异性结合的糖肽药物的(19)F。在最近邻肽主干中,d-和 l-丙氨酸之间观察到的(13)C-(15)N 平均距离为 4.1-4.4 Å,这与金黄色葡萄球菌肽聚糖中重复结构基序的局部、紧密堆积、平行主干结构一致。