Human pterin-4-alpha-carbinolamine dehydratase 2 (PCBD2A)

PCBD2

PDB:4C45

Revision

Revision Type:created
Revised by:created
Revision Date:created
Entry Clone Accession:IMAGE 6385036
Entry Clone Source:GeneScript
SGC Clone Accession:
Tag:N-terminal, TEV protease cleavable hexahistidine tag
Host:

Construct

Prelude:
Sequence:"MHHHHHHSSGVDLGTENLYFQSMSSGTHRLTAEERNQAILDLKAAGWSELSERDA IYKEFSFHNFNQAFGFMSRVALQAEKMNHHPEWFNVYNKVQITLTSHDCGELTKK DVKLAKFIEKAAASV"MHHHHHHSSGVDLGTENLYFQ*SM is the purification tag plus TEV protease recognition site *.
Vector:pNIC28-Bsa4

Growth

Medium:
Antibiotics:
Procedure:

Purification

Buffers
Procedure
Buffers Used:Binding/Lysis Buffer: 50 mM Hepes (pH 7.5), 500 mM NaCl, 5% Glycerol, 20 mM Imidazole pH 7.5, 0.01mM TCEP Wash Buffer: 50 mM Hepes (pH 7.5), 500 mM NaCl, 5% Glycerol, 40 mM Imidazole pH 7.5, 0.01mM TCEP Elution Buffer: 50 mM Hepes (pH 7.5), 500 mM NaCl, 5% Glycerol, 250 mM Imidazole pH 7.5, 0.01mM TCEPGel Filtration Buffer: 10 mM Hepes (pH 7.5), 500 mM NaCl, 5% Glycerol, 0.01mM TCEPCell LysisCell pellets were dissolved in approximately 50ml lysis buffer and broken by passing through the homogeniser (x6) at a constant pressure of 15KPa. The cell debris was pelleted at 16,000 RPM and the supernatant used for further purification.Column 1Ni-NTA (5.0 ml volume in a gravity-flow column).The clarified cell extract was incubated with 5.0 ml pre-equilibriated 50% Ni_NTA bead solution for 1 hour at 4°C with rotation after which it was passed through a glass column. The column was then washed with 30ml Binding Buffer (2 x 15ml) and 50 ml Wash Buffer (2 x15 ml). The protein was eluted with 25 ml of Elution Buffer in 5 x 5 ml fractions. Column 2Superdex s200 16/60 Gel Filtration. Elution fraction 1 was applied directly to the size exclusion chromatography column, s200 (pre-equilibriated in GF buffer). a second pool consiting of the combination (WB2+E2+E3) was concentrated to 5 ml (10 kDa mwco concentrator) and also applied to the GF column at 1.0 ml/min. 1.0 ml fractions were collected. Enzymatic treatment and purification The N-terminal His6- tag was cleaved by incubating overnight with TEV (20°C). Cleaved protein was purified by batch binding on 1ml pre-equilibriated 50% Ni-NTA bead solution. The column was then washed with 2x1ml Gel Filtration buffer,2x1ml Binding buffer, 2x1ml Wash buffer, and finally 2x1ml of Elution buffer.

Extraction

Buffers
Procedure
ExpressionExpression strainBL21(DE3)-R3-pRARE2 A glycerol stock was used to inoculate 2X60 ml of TB media containing 50mg/ml kanamycin and 50 ìg/ml chloramphenicol, which was placed in a 37°C shaker overnight. The next day this starter culture was used to inoculate 12L of TB media (10 ml starter culture used per 1L) containing 50 ìg/ml kanamycin. When the OD600 reached approximately 1.0 the temperature was reduced to 18°C and after a further 30 minutes the cells were induced by the addition of 0.1 mM IPTG. Expression was continued overnight.Cell harvestCells were harvested by centrifugation at 16,000 RPM after which the supernatant was poured out and the cell pellet either placed in a -80°C freezer or used directly for purification.
Concentration:To set up plates the sample was concentrated to 12.25 mg/ml using a 10 kDa mwco concentrator.
Ligand
MassSpec:Expected mass: 111848.4 Da Measured mass: ? Da
Crystallization:Crystals were grown by vapour diffusion in sitting drop at 20°C. A sitting drop consisting of 50 nl protein and 100nl well solution was equilibrated against well solution containing 2.4M sodium malonate.
NMR Spectroscopy:
Data Collection:Resolution: 1.45 Å X-ray source: Diamond Light Source beamline IO3
Data Processing: