Effects of Forced Solution Flow on Protein-Crystal Quality and Growth Process
Effects of Forced Solution Flow on Protein-Crystal Quality and Growth Process
复制标题
强制溶液流对蛋白质晶体质量和生长过程的影响
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
S. Yoda
中科院分区：
文献类型：
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作者：
Akio Kadowaki;I. Yoshizaki;S. Adachi;H. Komatsu;O. Odawara;S. Yoda
通过X射线衍射实验研究了强制溶液流动对蛋白质结晶质量的影响。流动生长蛋清溶菌酶的四方晶体，生长速度在0~1000μm/S范围内，流动生长的晶体质量优于静止生长的晶体。利用原子力显微镜(AFM)观察了(110)晶面的表面形貌，探讨了表面质量改善的机理。在静止条件下，二维(2D)核在表面上随机形成。在溶液流动作用下，在刻面中心周围形成了由2D孤岛组成的丘状结构。流动条件下的台阶密度高于静止条件下的台阶密度。由于阶梯密度的增大，阶梯生长速率随着流量的增加而减小。我们发现，晶体质量与阶跃生长速率之间存在着很强的相关性。结果表明，缓慢的生长减少了分子在扭结位置的择优取向，从而改善了晶体质量。
X-ray diffraction experiments were performed to study the effect of forced solution flow on protein-crystal quality. The tetragonal crystals of hen egg white lysozyme were grown under flow in the rate range of 0 (quiescent condition) to 1000 μm/s. The quality of the crystals grown under flow was superior to that of crystals grown under quiescent conditions. To investigate the mechanism of the quality improvement, we observed the surface morphology of the (110) face using atomic force microscopy (AFM). Under quiescent conditions, the two-dimensional (2D) nuclei were randomly formed over the surface. Under solution flow, a hillock consisting of 2D islands was formed around the facet center. The step density under flow was higher than that under quiescent conditions. The step growth rate decreased with increasing flow rate because of the step-density increase. We found that there was a strong correlation between the crystal quality and the step growth rate. The results suggested that the slow growth decreases the molecular misorientation at the kink site, resulting in an improvement in crystal quality.