Bergendahl, V., Anthony L. C., Heyduk, T., Burgess, R. R.
(2002)
Analytical Biochemistry,
307,
368-374 |
Recombinant Protein Expression,Protein Labeling |
N-terminal Hexahis tag + HMK recognition sequence |
Protein recombinantly expressed as and refolded from inclusion bodies. |
Escherichia coli |
BL21(DE3) |
37.0 |
2h |
pTA133 |
Cells grown in LB medium with 100microg/ml ampicillin. Cultures were grown, induced and then harvested by centrifugation(8,000g, 15min). The cell pellet was then re-suspended in 10ml NTGED buffer(50 mM NaCl, 50 mM TrisHCl, pH 7.5, 5% glycerol, 0.1 mM EDTA, 0.1 mM DTT) + 10mM EDTA and 100microg/ml lysozyme. This solution was then incubated on ice for 30min, prior to sonication at 4degC. After sonication 1% (v/v)Triton X-100 was added and the sample vortexed. Inclusion bodies were then separated by centrifugation(25,000g, 15min). |
IPTG |
OD 600 =
0.5-0.7 |
Sonication |
Lysozyme |
None |
insoluble |
Dilution |
50 mM NaCl, 50 mM TrisHCl, pH 7.5, 5% glycerol, 0.1 mM EDTA, 0.1 mM DTT, 0.1% Triton X-100 |
6 M GuHCl, 50 mM TrisHCl, 7.5, 5% glycerol, 0.1 mM EDTA |
50 mM TrisHCl, 5% glycerol, 0.1 mM EDTA |
None |
no |
7.5 |
20.0 |
n/a |
n/a |
DTT |
0.1 mM |
Inclusion bodies were washed with 10ml of washing buffer by a short sonication, prior to undergoing centrifugation(25,000g, 15min). The wash was then repeated with 10ml of washing buffer with 0.01% (v/v) Triton X-100. and suspension was aliquoted into 5 equal volumes, and underwent a final centrifugation at maximum speed. Supernatants were then discarded.
Inclusion bodies were solubilized in 5ml of Solublization buffer. Refolding was occurred by a 100 fold, preformed by dripping the solution into 500ml chilled refolding buffer on ice with slow stirring. If precipitation occured, it was removed by centriguation(25,000g, 15min, 4degC). Soluble refolded protein was then purified using anion-exchange resin in 5ml refolding buffer. Fractions were eluted using refolding buffer + 500mM NaCl. |
Ligand Binding |
None |
Glycerol,Triton X-100 |
5% |
n/a |
n/a |
n/a |