| X-RAY DIFFRACTION |
8.2 |
? |
Thrombin was purchased from Haematologic Technologies, Inc.
and acetyl-hirudin from Bachem. Thrombin was prepared as described
(Skrzpczak-Jankun et al., 1991). Thrombin (1.0 mg/ml in 50 mM HEPES, 50 %
glycerol, pH 7.0) was incubated with 1.0 mM acetyl-hirudin for 1 hr at
4 deg C. Glycerol was removed and the complex concentrated with a
centricon 10 (Amicon) to about 10 mg/ml as determined by the Biorad protein
assay kit using bovine serum albumin. Crystals of thrombin-acetyl-hirudin
were grown in hanging drops by vapor diffusion after streak seeding. The
drops were made from 5 microliters of complex and 5 microliters of reservoir
solution (0.10 M Tris, 0.50 M NaCl, 22 % (by volume) PEG 4K, pH 8.20)., VAPOR DIFFUSION |
