Radaev Sergei, Li Sean, Sun Peter D
Structural Immunology Section, National Institute of Allergy and Infectious Diseases, National Institutes of Health, 12441 Parklawn Drive, Rockville, Maryland 20852, USA.
Acta Crystallogr D Biol Crystallogr. 2006 Jun;62(Pt 6):605-12. doi: 10.1107/S0907444906011735. Epub 2006 May 12.
A survey of crystallization conditions was carried out for 650 published protein-protein complexes in the Protein Data Bank (PDB) of the Research Collaboratory for Structural Bioinformatics (RCSB). This resulted in the establishment of a Protein Complex Crystallization Database (PCCD) and a set of configuration-space boundaries for protein-complex crystallizations. Overall, polyethylene glycol (PEG) based conditions accounted for 70-80% of all crystallizations, with PEG 3000-4000, 5000-6000 and 8000 being the most frequently used. The median values of PEG concentrations were between 10 and 20% and were inversely correlated with their molecular weights. Ammonium sulfate remained the most favorable salt precipitant, with a median concentration of 1.6 M. The crystallization pH for the vast majority of protein complexes was between 5.0 and 8.0. Overall, the boundaries for the crystallization configuration space of protein complexes appear to be more restricted than those of soluble proteins. This may reflect the limited stability and solubility of protein-protein complexes. Based on statistical analysis of the database, a sparse-matrix and a systematic buffer and pH screen were formulated to best represent the crystallization of protein complexes.
对结构生物信息学研究合作实验室（RCSB）蛋白质数据库（PDB）中650个已发表的蛋白质 - 蛋白质复合物的结晶条件进行了调查。这促成了蛋白质复合物结晶数据库（PCCD）的建立以及一套蛋白质复合物结晶的构象空间边界。总体而言，基于聚乙二醇（PEG）的条件占所有结晶条件的70 - 80%，其中PEG 3000 - 4000、5000 - 6000和8000是最常用的。PEG浓度的中位数在10%至20%之间，且与它们的分子量呈负相关。硫酸铵仍然是最有利的盐沉淀剂，中位数浓度为1.6 M。绝大多数蛋白质复合物的结晶pH值在5.0至8.0之间。总体而言，蛋白质复合物结晶构象空间的边界似乎比可溶性蛋白质的边界限制更大。这可能反映了蛋白质 - 蛋白质复合物有限的稳定性和溶解性。基于对数据库的统计分析，制定了一个稀疏矩阵以及一个系统的缓冲液和pH筛选方案，以最佳地代表蛋白质复合物的结晶情况。
