Infrared protein crystallography.
Infrared protein crystallography.
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DOI：
10.1016/j.bbapap.2011.02.012
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发表时间：
2011-06
期刊：
影响因子：
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通讯作者：
J. Sage;Yunbin Zhang;J. McGeehan;J. McGeehan;R. Ravelli;R. Ravelli;M. Weik;J. V. Thor
中科院分区：
文献类型：
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作者：
J. Sage;Yunbin Zhang;J. McGeehan;J. McGeehan;R. Ravelli;R. Ravelli;M. Weik;J. V. Thor
我们考虑了红外光谱在蛋白质晶体中的应用，特别强调了通过取向单晶的偏振测量来研究分子取向。红外显微镜可以使用热源或非热源对单个晶体进行透射测量，并且可以容纳流动细胞，用于测量暴露于可溶性配体引起的光谱变化，以及用于测量闪冷晶体的低温流。通过对晶体和溶液的非偏振红外测量的比较，可以探测结晶的影响，并可以通过建立最相关的溶液条件来提高从x射线衍射数据中提炼出的结构模型的价值。对几种蛋白质的分析结果与晶体和溶液中相似的平衡构象分布一致。然而，构象变化的速率经常受到干扰。红外测量还可以检测x射线照射产生的产物，包括二氧化碳。具有良好对称性的晶体表现出红外二色性，增强了与x射线晶体学的协同作用。对晶体的偏振红外测量可以区分化学相似位点的光谱贡献，识别氢键伙伴，并在适当的情况下确定分子群的三维取向。这篇文章是题为“晶体状态下的蛋白质结构和功能”的特刊的一部分。
We consider the application of infrared spectroscopy to protein crystals, with particular emphasis on exploiting molecular orientation through polarization measurements on oriented single crystals. Infrared microscopes enable transmission measurements on individual crystals using either thermal or nonthermal sources, and can accommodate flow cells, used to measure spectral changes induced by exposure to soluble ligands, and cryostreams, used for measurements of flash-cooled crystals. Comparison of unpolarized infrared measurements on crystals and solutions probes the effects of crystallization and can enhance the value of the structural models refined from X-ray diffraction data by establishing solution conditions under which they are most relevant. Results on several proteins are consistent with similar equilibrium conformational distributions in crystal and solutions. However, the rates of conformational change are often perturbed. Infrared measurements also detect products generated by X-ray exposure, including CO2. Crystals with favorable symmetry exhibit infrared dichroism that enhances the synergy with X-ray crystallography. Polarized infrared measurements on crystals can distinguish spectral contributions from chemically similar sites, identify hydrogen bonding partners, and, in opportune situations, determine three-dimensional orientations of molecular groups. This article is part of a Special Issue entitled: Protein Structure and Function in the Crystalline State.