Cross-linking of protein crystals as an aid in the generation of binary protein-ligand crystal complexes, exemplified by the human PDE10a-papaverine structure
Cross-linking of protein crystals as an aid in the generation of binary protein-ligand crystal complexes, exemplified by the human PDE10a-papaverine structure
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DOI：
10.1107/s0907444909017855
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发表时间：
2009-08-01
影响因子：
2.2
通讯作者：
Barker, John
中科院分区：
文献类型：
--
作者：
Andersen, Ole Andreas;Schoenfeld, Dorian Leo;Barker, John
蛋白质结晶学已被证明是获得蛋白质-配体复合体高分辨结构的有效方法。然而，在某些情况下，只有载脂蛋白结构是现成的，而晶体复合体的产生更有问题。由于晶体堆积效应，一些结晶学体系不适用于配体的浸泡，许多蛋白质-配体复合体在与脱辅基蛋白相同的条件下不结晶。以人磷酸二酯酶10a(HPDE10a)的晶体为例，在浸泡配体之前，用戊二醛交联的蛋白质晶体，获得了罂粟碱配合物的结构，分辨率达到2.8埃。对电子密度图的检查表明，在不对称单元中的两种单体中的一种获得了正确的结合模式，而对晶体填充接触的检查解释了为什么共结晶实验和未交联的晶体的浸泡不成功。
Protein crystallography has proven to be an effective method of obtaining high-resolution structures of protein-ligand complexes. However, in certain cases only apoprotein structures are readily available and the generation of crystal complexes is more problematic. Some crystallographic systems are not amenable to soaking of ligands owing to crystal-packing effects and many protein-ligand complexes do not crystallize under the same conditions as used for the apoprotein. Using crystals of human phosphodiesterase 10a (hPDE10a) as an example of such a challenging crystallographic system, the structure of the complex with papaverine was obtained to 2.8 angstrom resolution using protein crystals cross-linked by glutaraldehyde prior to soaking of the ligand. Inspection of the electron-density maps suggested that the correct mode of binding was obtained in one of the two monomers in the asymmetric unit and inspection of crystal-packing contacts explained why cocrystallization experiments and soaking of crystals that were not cross-linked were unsuccessful.