Crystallization and preliminary X-ray analysis of active site-inhibited human coagulation factor VIIa (des-Gla).

Human coagulation factor VIIai that lacks the Gla domain (residues 1-44) has been prepared, purified, and crystallised. First, recombinant factor VII was activated to form factor VIIa, the active site was then inhibited with 1,5-dansyl-Glu-Gly-Arg-chloromethyl ketone, and finally the Gla domain was removed by chymotryptic digestion, yielding factor VIIai (des-Gla). After further purification single crystals suitable for x-ray analysis were obtained by vapour diffusion. Crystals of factor VIIai (des-Gla) belong to the tetragonal space group P41212 or P43212 with unit cell dimensions a = b = 94.85 A, c = 114.30 A, contain one molecule per asymmetric unit, and diffract to 2.3-A resolution when exposed to synchrotron radiation.