Gangloff Monique, Moreno Abel, Gay Nicholas J
Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge CB2 1GA, UK.
J Appl Crystallogr. 2013 Apr 1;46(Pt 2):337-345. doi: 10.1107/S0021889812051606. Epub 2013 Feb 14.
Generating high-quality crystals remains a bottleneck in biological and materials sciences. Here a counter-diffusion method was used to improve the X-ray diffraction quality of the N-terminal domain of Toll receptor crystals. It was observed that crystallization occurred with a peculiar pattern along the capillary resembling Liesegang bands; this phenomenon is described at both macroscopic and atomic levels. It was found that bands appeared for native protein as well as for co-crystals of magic triangle (I3C)-bound protein even though they crystallize in different space groups. Crystallization occurred with a linear recurrence independent of the precipitant concentration and a protein-specific spacing coefficient. Bandwidth varied along the capillary, oscillating between large precipitation areas and single crystals. The reported data suggest that repetitive patterns can be generated with biological macromolecules in the presence of sodium malonate as a crystallization agent. A comparison with typical Liesegang patterns and the possible mechanism underlying this phenomenon are discussed.
生成高质量晶体仍然是生物科学和材料科学中的一个瓶颈。在此，采用了一种反向扩散方法来提高Toll受体晶体N端结构域的X射线衍射质量。观察到沿毛细管出现了类似于李赛格环带的特殊结晶模式；这一现象在宏观和原子水平上均有描述。结果发现，天然蛋白质以及与魔三角（I3C）结合的蛋白质的共晶体都会出现条带，尽管它们结晶于不同的空间群。结晶以与沉淀剂浓度和蛋白质特异性间距系数无关的线性递归方式发生。带宽沿毛细管变化，在大沉淀区域和单晶之间振荡。所报道的数据表明，在丙二酸钠作为结晶剂的情况下，生物大分子可以产生重复模式。本文还讨论了与典型李赛格模式的比较以及该现象背后可能的机制。
