Sunday, August 22, 2010

Move forward!

This week will be a busy week starting from tomorrow.
Maybe should say it is a busy month too.

I do not want to waste my time anymore. So let's get to work.

An amount of bacterial hosts and expression vectors appearing in my minds now.
The classic - BL21(DE3) and BL21(DE3) pLysS.
The hybrid of origami and rossetta - Rosetta-gami2(DE3)
The NEB express - ER2523
+
pET32 Xa/Lic
pCold1 Xa
pMAL -c5x
pMAL -p5x

Good luck and all the best to me!
As well as the revival of glycerol stock of my precious Rosetta-gami2(DE3)pET32-PhaCcs which used to produce soluble PhaCcs.

Wednesday, August 18, 2010

Insoluble protein?!

According to SDS P.A.G.E for solubility which I did on 18 AUG, the result doesn't looks good.

No PhaC protein on the soluble fraction; but a estimated ~15% expressed PhaC in insoluble fraction. [Troubleshooting: I still got other stock, will sonicate other bacterial cells and check again]

Maybe it is better to subclone the stored plasmid to Rosetta-gami2 (DE3) and BL21 (DE3) , BL21 (DE3)/pLySs?
At the same time, design primer and clone into pCold and pMAL.

Will email Dr after I have troubleshoot for insolubility and plan the cloning experiments in this weekend.

Monday, August 16, 2010

August

Last 2 weeks screening for the culture of RG2 pET32 phaCcs between 2 culture from glycerol stock.

As a result, one of the bacteria was contamination, didn't express protein phaC and didnt contain the correct plasmids.

Then I continue to culture and induce the correct bacteria with a total amount of 2 litre media. (5 X 400ml culture)

After last weekend rest, I'm ready to continue to the next step, here is the plan.

17 AUG 2010 (Done)
1. SDS PAGE (for total protein expression)

18 AUG 2010
1. Sonication for 400ml culture (2 X 250ml centrifuge tube culture, others were kept for further uses at -20C) (DONE)
2. SDS PAGE (to check the solubility) (DONE)
3. PhaC temperature stability test. (just choose 2 different temperature, 4C and RT ~25C, I'm wondering the stability of my PhaC protein, so just wanna get more information about its degradation rate.) (Reschedule to 19 AUG, need to use pure protein)

19 AUG 2010
1. Purification by TALON
2. Purification by denatured conditions (TALON as well, doing this to check whether the suspicious 30kDa protein is the complex of PhaC protein or not)
3. SDS PAGE (to check the purity)

20 AUG 2010
1. Gel filtration (optimized condition, slower flow rate, smaller volume sample)
2. SDS PAGE

21/22 AUG 2010
1. PhaC enzyme activity assay (Joanne)

*Progress of the plan flow will be indicated and post will be edited accordingly.
Also as a guideline to push my laziness away.
*At the same time, 20AUG2010 will be our small group meeting for the structure of PhaC review which is 1 week later than our predicted schedule.