CRYSTALLIZATION AND X-RAY-DIFFRACTION DATA OF THE CLEAVED FORM OF PLASMINOGEN-ACTIVATOR INHIBITOR-1

To characterize the structural requirements for the conformational fle xibility in plasminogen activator inhibitor-1 (PAI-1) we have crystall ized human PAI-1, carrying a mutation which stabilizes PAI-1 in its su bstrate form. Crystallization was performed by the hanging drop diffus ion method at pH 8.5 in the presence of 19% (w/v) polyethyleneglycol 4 000 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 Angstrom, b = 47.5 Angstrom, c = 62.7 Angstrom, and beta = 11 3.9 degrees, and one molecule in the asymmetric unit. The X-ray diffra ction data set contains data with a limiting resolution of 2.5 Angstro m. Biochemical analysis of the redissolved crystals indicated that dur ing the crystallization process, cleavage had occurred in the active s ite loop at the P1-P1' position. The availability of good-quality crys tals of the cleaved form of this serpin will allow its three-dimension al structure to be solved and will provide detailed information on the structure function relationship in PAI-1. (C) 1995 Wiley-Liss, Inc.