Zang L H, Rothman D L, Shulman R G
Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT 06510.
Proc Natl Acad Sci U S A. 1990 Mar;87(5):1678-80. doi: 10.1073/pnas.87.5.1678.
High-resolution 1H NMR spectra of rabbit liver glycogen in 2H2O were obtained at 500 MHz, and several resonances were assigned by comparison with the chemical shifts of alpha-linked diglucose molecules. The NMR relaxation times T1 and T2 of glycogen in 2H2O were determined to be 1.1 and 0.029 s, respectively. The measured natural linewidth of the carbon-1 proton (12 +/- 2 Hz) is in excellent agreement with that calculated from T2. The visibility measurements made by digesting glycogen and comparing glucose and glycogen signal intensities demonstrate that in spite of the very high molecular weight, all of the proton nuclei in glycogen contribute to the NMR spectrum. The result is not unexpected, since 100% NMR visibility was previously observed from the carbon nuclei of glycogen, due to the rapid intramolecular motions.
在500兆赫下获得了兔肝糖原在重水中的高分辨率1H核磁共振谱，并通过与α-连接的二葡萄糖分子的化学位移进行比较，确定了几个共振峰。重水中糖原的核磁共振弛豫时间T1和T2分别测定为1.1秒和0.029秒。测得的碳-1质子的天然线宽（12±2赫兹）与根据T2计算得到的值非常吻合。通过消化糖原并比较葡萄糖和糖原信号强度进行的可见性测量表明，尽管糖原分子量非常高，但糖原中的所有质子核都对核磁共振谱有贡献。这一结果并不意外，因为由于分子内的快速运动，之前已观察到糖原的碳核具有100%的核磁共振可见性。
