Aertgeerts K, De Bondt H L, De Ranter C, Declerck P J
Laboratory for Analytical Chemistry and Medicinal Physicochemistry, Faculty of Pharmaceutical Sciences, Katholieke Universiteit Leuven, Belgium.
Proteins. 1995 Sep;23(1):118-21. doi: 10.1002/prot.340230114.
To characterize the structural requirements for the conformational flexibility in plasminogen activator inhibitor-1 (PAI-1) we have crystallized human PAI-1, carrying a mutation which stabilizes PAI-1 in its substrate form. Crystallization was performed by the hanging drop diffusion method at pH 8.5 in the presence of 19% (w/v) polyethyleneglycol 4000 as a precipitant. The crystals appear after 3 days at 23 degrees C and belong to the monoclinic space group C2 with cell dimensions of a = 151.8 A, b = 47.5 A, c = 62.7 A, and beta = 113.9 degrees, and one molecule in the asymmetric unit. The X-ray diffraction data set contains data with a limiting resolution of 2.5 A. Biochemical analysis of the redissolved crystals indicated that during the crystallization process, cleavage had occurred in the active site loop at the P1-P1' position. The availability of good-quality crystals of the cleaved form of this serpin will allow its three-dimensional structure to be solved and will provide detailed information on the structure-function relationship in PAI-1.
为了表征纤溶酶原激活物抑制剂-1（PAI-1）构象灵活性的结构要求，我们使携带一个能将PAI-1稳定在其底物形式的突变的人PAI-1结晶。结晶是通过悬滴扩散法在pH 8.5、存在19%（w/v）聚乙二醇4000作为沉淀剂的条件下进行的。晶体在23℃下3天后出现，属于单斜空间群C2，晶胞参数为a = 151.8 Å，b = 47.5 Å，c = 62.7 Å，β = 113.9°，不对称单位中有一个分子。X射线衍射数据集包含分辨率极限为2.5 Å的数据。对重新溶解的晶体的生化分析表明，在结晶过程中，活性位点环在P1-P1'位置发生了切割。这种丝氨酸蛋白酶抑制剂切割形式的高质量晶体的可得性将使其三维结构得以解析，并将提供关于PAI-1结构-功能关系的详细信息。
