1C1U

RECRUITING ZINC TO MEDIATE POTENT, SPECIFIC INHIBITION OF SERINE PROTEASES

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	ROTATING ANODE
Temperature [K]	298
Detector technology	IMAGE PLATE
Collection date	1998-01-23
Detector	RIGAKU RAXIS IV++
Spacegroup name	C 1 2 1
Unit cell lengths	71.680, 72.120, 73.110
Unit cell angles	90.00, 101.62, 90.00

Refinement procedure

Resolution	7.500 - 1.750
R-factor	0.206
Rwork	0.206
R-free	0.23500
Structure solution method	DIFFERENCE FOURIER PLUS REFINEMENT
RMSD bond length	0.018
RMSD bond angle	4.100
Data reduction software	bioteX ((MSC))
Data scaling software	bioteX
Phasing software	X-PLOR
Refinement software	X-PLOR (3.1)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	38.780	1.830
High resolution limit [Å]	1.450	1.750
Rmerge	0.085	0.250
Number of reflections	35066
<I/σ(I)>	7.8	1.8
Completeness [%]	77.0	50
Redundancy	1.9

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	unknown *	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, 1.0 MM HEMI-BABIM, 1.0 MM ZN+2 FOR 1 HR AT 4 DEG C. GLYCEROL WAS REMOVED AND THE COMPLEX CONCENTRATED WITH A CENTRICON 10 ( AMICON) TO 8.6 MG/ML AS DETERMINED BY THE BIORAD PROTEIN ASSAY KIT USING BOVINE SERUM ALBUMIN. CRYSTALS OF THROMBIN-ACETYL-HIRUDIN-HEMI-BABIM-ZN+2 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).