DEVELOPMENT OF A BIOSUPRAMOLECULAR NMR SYSTEM WITH A SUPERCONDUCTING MAGNET

我们的AM-400核磁共振光谱仪（Bruker）内置了一个多核观测系统。然后，研制了一种固体氘核磁共振探针头。采用四极回波脉冲序列进行测量。首先，一个电磁线圈是建立在探头，最初用于溶液核磁共振。90瓣脉冲为12µs。对探头和匹配盒的电路进行了简化。修改后，90瓣脉冲变成了4mus左右。因此，我们建立了固态核磁共振系统，可以作为本项目的起点。在甘油主链中特异氘化的磷脂是从存在过氘化甘油中培养的大肠杆菌细胞中获得的。由于生物样品中含有水，因此样管应垂直放置。虽然电磁线圈中的功率非常有效，但样管保持水平。所以我们决定改变线圈的设计。鞍型线圈附着在5毫米厚的玻璃管表面，垂直放置。8转线圈适合0.94厘米^3样品体积。该线圈的90 / h脉冲为7.8 μ s。为了获得更大的功率，连接了一个高功率放大器。然而，拱发生在探头头在使用这种放大器。由于我们的磁铁的孔径很窄，探头不足以避免拱起。在没有放大器的情况下检查探针。用60 mg氘化磷脂，得到了高质量的^2H-NMR谱。用反演恢复法测量了自旋-晶格弛豫时间。功率谱的整个区域被180个<s:1>脉冲反转。结果表明，该线圈可用于磷脂双分子层的研究。因此，我们成功地建立了一个适合生物膜研究的固态核磁共振系统。

A multinuclear observation system was built into our AM-400 NMR spectrometer (Bruker). Then, a solid-state probe head for deuterium NMR was developed. The quadrupole echo pulse sequence was used for the measurements. At first, a solenoid coil was built in a probe head, originally used for solution NMR. The 90ﾟ pulse was 12mus. The circuits of the probe head and matching box were simplified. After the modification, the 90ﾟ pulse became to be about 4mus. Thus, we have established the solid-state NMR system, which can be used for the start point of this project. phospholipids specifically deuterated in the glycerol backbone were obtained from E. coli cells cultured in the presence of perdeuterated glycerol.Since biological samples contain water, the sample tube should be held vertically. Although the power is very efficient in the solenoid coil, the sample tube is kept in horizontal. So we decided to change the coil design. A saddle type coil was attached on the surface of a glass tube with 5 mmphi, which was put in the vertical direction. The 8-turn coil fits to 0.94 cm^3 sample volume. The 90ﾟ pulse of this coil was 7.8mus. In order to get more power, a high power amplifier was connected. However, arching took place in the probe head on the use of this amplifier. Since the bore size of our magnet is narrow, the probe is not enough to avoid the arching. The probe was examined without the amplifier. By using 60 mg deuterated phospholipids, a ^2H-NMR spectrum in good quality was obtained. The spin-lattice relaxation time was measured using the inversion-recovery method. Whole region of the power pattern spectrum was inverted by the 180ﾟ pulse. These results show that this coil can be used for the investigation of the phospholipid bilayers. Thus, we have succeeded in establishing a solid-state NMR system suitable for biomembrane studies.