English A C, Done S H, Caves L S, Groom C R, Hubbard R E
Department of Chemistry, University of York, Heslington, United Kingdom.
Proteins. 1999 Dec 1;37(4):628-40.
Multiple-solvent crystal structure determination (MSCS) allows the position and orientation of bound solvent fragments to be identified by determining the structure of protein crystals soaked in organic solvents. We have extended this technique by the determination of high-resolution crystal structures of thermolysin (TLN), generated from crystals soaked in 2% to 100% isopropanol. The procedure causes only minor changes to the conformation of the protein, and an increasing number of isopropanol interaction sites could be identified as the solvent concentration is increased. Isopropanol occupies all four of the main subsites in the active site, although this was only observed at very high concentrations of isopropanol for three of the four subsites. Analysis of the isopropanol positions shows little correlation with interaction energy computed using a molecular mechanics force field, but the experimentally determined positions of isopropanol are consistent with the structures of known protein-ligand complexes of TLN.
多溶剂晶体结构测定（MSCS）通过测定浸泡在有机溶剂中的蛋白质晶体结构，来确定结合溶剂片段的位置和取向。我们通过测定嗜热菌蛋白酶（TLN）的高分辨率晶体结构扩展了这项技术，这些晶体是由浸泡在2%至100%异丙醇中的晶体生成的。该过程仅使蛋白质构象发生微小变化，并且随着溶剂浓度的增加，可以识别出越来越多的异丙醇相互作用位点。异丙醇占据了活性位点的所有四个主要亚位点，尽管只有在非常高浓度的异丙醇下，四个亚位点中的三个才观察到这种情况。对异丙醇位置的分析表明，其与使用分子力学力场计算的相互作用能几乎没有相关性，但实验确定的异丙醇位置与TLN已知蛋白质-配体复合物的结构一致。
