1CPX

BETA FORM OF CARBOXYPEPTIDASE A (RESIDUES 3-307) FROM BOVINE PANCREAS IN AN ORTHORHOMBIC CRYSTAL FORM WITH TWO ZINC IONS IN THE ACTIVE SITE.

Experimental procedure

Experimental method	SINGLE WAVELENGTH
Source type	ROTATING ANODE
Source details	RIGAKU RU200
Temperature [K]	290
Detector technology	IMAGE PLATE
Collection date	1996-12-06
Detector	RIGAKU RAXIS II
Spacegroup name	P 21 21 21
Unit cell lengths	48.790, 66.850, 96.020
Unit cell angles	90.00, 90.00, 90.00

Refinement procedure

Resolution	8.000 - 2.000
R-factor	0.167
Rwork	0.167
R-free	0.22600
Structure solution method	MOLECULAR REPLACEMENT
Starting model (for MR)	5CPA WITHOUT WATERS AND ZN
RMSD bond length	0.010
RMSD bond angle	22.400 *
Data reduction software	DENZO
Data scaling software	SCALEPACK
Phasing software	AMoRE
Refinement software	X-PLOR (3.851)

Data quality characteristics

	Overall	Outer shell
Low resolution limit [Å]	40.000	2.030
High resolution limit [Å]	2.000	2.000
Rmerge	0.038	0.157
Number of reflections	20453
<I/σ(I)>	30.7	7.1
Completeness [%]	94.1	67.7
Redundancy	4.3	3.9

Crystallization Conditions

crystal ID	method	pH	temperature	details
1	MICRODIALYSIS	7.5		CPA FROM SIGMA #C0261 WAS DISSOLVED IN 1.0 M LICL WITH 20 MM TRIS-HCL PH 7.5 TO GIVE 12 MG/ML AND USED WITHOUT FURTHER PURIFICATION. THIS PROTEIN SOLUTION WAS PLACED IN 50 MICROL DIALYSIS BUTTONS FROM HAMPTON RESEARCH AND DIALYZED AGAINST A 2 ML RESERVOIR OF THE ABOVE MENTIONED BUFFER WHILE LOWERING THE EXTERNAL LICL CONCENTRATION BY 25% EVERY OTHER DAY. THE CRYSTALS APPEARED A~0.24 M LICL AND WAS STORED AT 0.30M LICL. IF THIS PROCEDURE DOES NOT WORK BY ITSELF AND YOU END UP WITH THE MONOCLINIC ALPHA-FORM (1-307), YOU CAN TRY TO AD TRACES OF TRYPSIN (~10 MICROG/ML) TO THE PROTEIN SOLUTION TO PROVOKE FORMATION OF THE BETA-FORM (3-307), micro dialysis

Crystallization Reagents in Literatures

ID	crystal ID	solution	reagent name	concentration (unit)	details
1	1	1		1.0 (M)
2	1	1	Tris-HCl	20 (mM)
3	1	2		0.24 (M)