Dialysis |
Milli-Q water |
4.5M urea, 10mM Tris, 0.1M 2-mercaptoethanol |
1:10mM Tris pH 11.0, 0.1mM 2-mercaptoethanol, 1mM cysteine, 5% glycerol, 2: 10mM TrisHCl pH 8.8, 1mM 2-mercaptoethanol |
None |
no tag |
8.8 |
4.0 |
|
104h |
Cysteine |
1mM |
Cells were grown in LB medium, when OD600 reached 0.3, protein expression was induced with 0.1mM IPTG, cells were incubated for a further 16h at 37degC. The cells were harvested by centrifugation (30min x 4000g), the pellet was then suspended and mixed with ice-cold lysis buffer 1 (50mM TrisHCl, pH 7.8, 200mM NaCl, 0.1mM EDTA, 5% glycerol) followed by the addition of 1/10 volume of lysis buffer 2 (50mM EDAT, 10% Triton X-100). Lysozyme was also added (final concentration 0.01mg/ml) and the mixture was incubated on ice for 3h. The cells were then sonicated and DNAseI added (final concentration 0.3micrograms/ml) and the mixture incubated for 1h at 37degC. The lysate was then centrifuged (30min x4000g) and the insoluble pellet was washed twice with ice-cold Milli-Q water. The entire lysis process was then repeated.
The pellet was then dissolved in solubilization buffer and the mixture was adjusted to pH 12 with NaOH to completely dissolve the proteins. The mixture was centrifuged (30min x 4000g) and the pellet removed. The supernatant was then dialyzed against refolding buffer 1 containing 1M urea for 72h at 4degC. The urea was then removed by dialysis against refolding buffer 1 for 24h at 4degC. The mixture was then dialyzed against refolding buffer 2 containing 5% glycerol for 4hr at 4degC, followed by dialysis against refolding buffer 2 for 4h at 4degC. |
Bioactivity |
None |
None,Glycerol |
5% |
|
96% |
Step-wise dialysis refolding method
Same protocol for Epiniephelus awoara growth hormone
UniProt ID: Q8UW03_PLEAT
Sequence:
ASGSENQRLFS IAVNRAQHLH LLAQKMFNDF EGNLSPDDRR
QMNKIFLQDF CNSDSIISPV DKHETQKSSV QKLLHISFRL VESWEYPSQA LSSSLSLSRF SEIPLKLTDL KLGIDTILRG TQDGLLSLED NEAQQLPPYE NYYQNLGGDD NIHRSYELLA CFKKDMHKVE TYLTVAKCRR SLEANCTL
Number of amino acids: 189
Molecular weight: 21626.4
Theoretical pI: 5.87
|