| X-RAY DIFFRACTION |
7.5 |
? |
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, 10 mM benzamidine 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-benzmaidine 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 7.5)., VAPOR DIFFUSION |
