Lapidot A, Irving C S
Proc Natl Acad Sci U S A. 1977 May;74(5):1988-92. doi: 10.1073/pnas.74.5.1988.
The proton-decoupled 15N Fourier transform nuclear magnetic resonance (NMR) spectra of 15N-enriched Escherichia coli, Bacillus licheniformis, baker's yeast, and Friend leukemic cells were obtained. The 15N NMR spectra of whole cells displayed 15N resonances originating from (i) protein backbones with lysine, arginine, and histidine side chains, (ii) ribonucleic acids, (iii) peptidoglycan, and (iv) phospholipids. Several additional amino and amide resonances were observed but not identified. In bacteria and yeast, the cell wall was found to be the site of a relatively mobile group of molecules, whose resonances dominate the proton-decoupled 15N NMR spectra of whole cells. 15N NMR chemical shifts and nuclear Overhauser effects have provided information on the in vivo structure of cell wall peptidoglycan. In Staphylococcus aureus the pentaglycine cross-bridge of cell wall peptidoglycan was found to have a random coil conformation. In B. licheniformis considerable segmental motional freedom was detected in teichuronic acid and peptidoglycan polysaccharide chains in the wall of the intact cell.
获得了富含¹⁵N的大肠杆菌、地衣芽孢杆菌、面包酵母和弗瑞德白血病细胞的质子去耦¹⁵N傅里叶变换核磁共振（NMR）谱。全细胞的¹⁵N NMR谱显示出¹⁵N共振信号，其来源于：（i）带有赖氨酸、精氨酸和组氨酸侧链的蛋白质主链；（ii）核糖核酸；（iii）肽聚糖；（iv）磷脂。还观察到了一些额外的氨基和酰胺共振信号，但未进行鉴定。在细菌和酵母中，发现细胞壁是一组相对可移动分子的所在位置，其共振信号在全细胞的质子去耦¹⁵N NMR谱中占主导。¹⁵N NMR化学位移和核Overhauser效应提供了关于细胞壁肽聚糖体内结构的信息。在金黄色葡萄球菌中，发现细胞壁肽聚糖的五甘氨酸交联桥具有无规卷曲构象。在地衣芽孢杆菌中，在完整细胞壁的磷壁酸和肽聚糖多糖链中检测到了相当程度的局部运动自由度。
