Glucksman M J, Hay R D, Makowski L
Science. 1986 Mar 14;231(4743):1273-6. doi: 10.1126/science.3945822.
A simple system was developed for obtaining x-ray diffraction patterns from magnetically oriented solutions of macromolecular assemblies. A small permanent magnet was designed that produces a magnetic field of 16 kilogauss in a volume of 1 cubic millimeter and is mountable on most x-ray cameras. Many subcellular structures have sufficient diamagnetic anisotropy that they exhibit orientation in dilute solution when placed between the poles of the magnet. Diffraction from solutions oriented in this magnet can provide substantially more structural information than small-angle scattering from isotropic solutions. In favorable cases, such as dilute solutions of filamentous bacteriophages, it is possible to produce oriented fiber diffraction patterns from which intensities along layer lines can be measured to 7-angstrom resolution. The magnetically induced birefringence observed in solutions of other macromolecular assemblies suggests that this technique may have broad applicability to subcellular structures.
开发了一种简单的系统，用于从大分子聚集体的磁取向溶液中获取X射线衍射图谱。设计了一种小型永磁体，它在1立方毫米的体积内产生16千高斯的磁场，并且可以安装在大多数X射线相机上。许多亚细胞结构具有足够的抗磁各向异性，以至于当置于磁体两极之间时，它们在稀溶液中会表现出取向。这种磁体中取向溶液的衍射比各向同性溶液的小角散射能提供更多的结构信息。在有利的情况下，如丝状噬菌体的稀溶液，可以产生取向纤维衍射图谱，从中可以测量到沿层线的强度，分辨率可达7埃。在其他大分子聚集体溶液中观察到的磁致双折射表明，该技术可能对亚细胞结构具有广泛的适用性。
