The first protein crystal structure determined from high-resolution X-ray powder diffraction data: a variant of T3R3 human insulin-zinc complex produced by grinding.
The first protein crystal structure determined from high-resolution X-ray powder diffraction data: a variant of T3R3 human insulin-zinc complex produced by grinding.
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根据高分辨率 X 射线粉末衍射数据确定的第一个蛋白质晶体结构：通过研磨产生的 T3R3 人胰岛素锌复合物的变体。
DOI：
10.1107/s0907444900013901
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
Blessing,RH
中科院分区：
文献类型：
--
作者：
VonDreele,RB;Stephens,PW;Smith,GD;Blessing,RH
蛋白质结构的X射线衍射分析通常受到合适晶体可用性的限制。然而，单晶的缺乏在蛋白质晶体学中并不一定比在材料科学中更成为不可逾越的障碍，在材料科学中，粉末衍射技术已经发展到可以仅从粉末数据解决复杂氧化物，沸石和小有机分子结构的地步。在这里，这一事实是证明与结构的解决方案和细化的T3 R3锌-人胰岛素复合物的一个新的变种产生的机械研磨的多晶样品。高分辨率的同步辐射X射线粉末衍射数据被用来解决这个晶体结构的Rietveld细化的分子置换。将7981个立体化学约束与4800步（dmin = 3.24 nm）的粉末衍射图相结合，对1630个原子的蛋白质进行了完全的Rietveld精修，得到Rwp = 3.73%，Rp = 2.84%，R_{F}^{2} = 8.25%. 据确定，研磨诱导的相变是伴随着9.5和17.2°旋转的两个T3 R3复合物，包括晶体结构。该材料在2-3天内回复以恢复原始T3 R3晶体结构。 用Rietveld方法对该蛋白质进行了精修，得到了Rwp = 3.46%，Rp = 2.64%，R_{F}^{2}= 7.10%，其中Rwp = 3.46%，R_{F}^{2} = 7.10%. 所证明的解决和细化蛋白质晶体结构的能力，从粉末衍射数据表明，这种方法可以采用，例如，检查一系列蛋白质衍生物的结构变化，其中一个成员的结构是已知的单晶研究。
X-ray diffraction analysis of protein structure is often limited by the availability of suitable crystals. However, the absence of single crystals need not present an insurmountable obstacle in protein crystallography any more than it does in materials science, where powder diffraction techniques have developed to the point where complex oxide, zeolite and small organic molecular structures can often be solved from powder data alone. Here, that fact is demonstrated with the structure solution and refinement of a new variant of the T3R3 Zn–human insulin complex produced by mechanical grinding of a polycrystalline sample. High-resolution synchrotron X-ray powder diffraction data were used to solve this crystal structure by molecular replacement adapted for Rietveld refinement. A complete Rietveld refinement of the 1630-atom protein was achieved by combining 7981 stereochemical restraints with a 4800-step (dmin = 3.24 Å) powder diffraction pattern and yielded the residuals Rwp = 3.73%, Rp = 2.84%, R_{F}^{2} = 8.25%. It was determined that the grinding-induced phase change is accompanied by 9.5 and 17.2° rotations of the two T3R3 complexes that comprise the crystal structure. The material reverts over 2–3 d to recover the original T3R3 crystal structure. A Rietveld refinement of this 815-atom protein by combining 3886 stereochemical restraints with a 6000-step (dmin = 3.06 Å) powder diffraction pattern yielded the residuals Rwp = 3.46%, Rp = 2.64%, R_{F}^{2} = 7.10%. The demonstrated ability to solve and refine a protein crystal structure from powder diffraction data suggests that this approach can be employed, for example, to examine structural changes in a series of protein derivatives in which the structure of one member is known from a single-crystal study.