Stelter Meike, Molina Rafael, Jeudy Sandra, Kahn Richard, Abergel Chantal, Hermoso Juan A
University Grenoble Alpes, Institut de Biologie Structurale (IBS), Grenoble, France.
Structural Biology and Biocomputing Programme, Spanish Cancer Research Centre (CNIO), Melchor Fdez Almagro, 28029 Madrid, Spain.
Acta Crystallogr D Biol Crystallogr. 2014 Jun;70(Pt 6):1506-16. doi: 10.1107/S1399004714005483. Epub 2014 May 23.
A set of seven caged gadolinium complexes were used as vectors for introducing the chelated Gd(3+) ion into protein crystals in order to provide strong anomalous scattering for de novo phasing. The complexes contained multidentate ligand molecules with different functional groups to provide a panel of possible interactions with the protein. An exhaustive crystallographic analysis showed them to be nondisruptive to the diffraction quality of the prepared derivative crystals, and as many as 50% of the derivatives allowed the determination of accurate phases, leading to high-quality experimental electron-density maps. At least two successful derivatives were identified for all tested proteins. Structure refinement showed that the complexes bind to the protein surface or solvent-accessible cavities, involving hydrogen bonds, electrostatic and CH-π interactions, explaining their versatile binding modes. Their high phasing power, complementary binding modes and ease of use make them highly suitable as a heavy-atom screen for high-throughput de novo structure determination, in combination with the SAD method. They can also provide a reliable tool for the development of new methods such as serial femtosecond crystallography.
一组七个笼状钆配合物被用作载体，将螯合的钆离子引入蛋白质晶体中，以便为从头相位测定提供强反常散射。这些配合物包含带有不同官能团的多齿配体分子，以提供一系列与蛋白质可能的相互作用。详尽的晶体学分析表明，它们对所制备的衍生物晶体的衍射质量无干扰，多达50%的衍生物能够确定精确的相位，从而得到高质量的实验电子密度图。对于所有测试的蛋白质，至少鉴定出两种成功的衍生物。结构精修表明，这些配合物结合在蛋白质表面或溶剂可及的腔中，涉及氢键、静电和CH-π相互作用，解释了它们多样的结合模式。它们的高相位能力、互补的结合模式和易用性使其非常适合作为与单波长反常散射法相结合的高通量从头结构测定的重原子筛选工具。它们还可为诸如串联飞秒晶体学等新方法的开发提供可靠工具。
