Team:UCLA/Notebook/Honeybee Silk/29 July 2015
Honeybee Inclusion Body Purification
- Pre weigh two 50 ml falcon tubes
- Split the culture into two 50 ml falcon tubes.
- Mass balance and spin down cells at 5300 rpm 4C for 15 minutes.
- Decant supernatant, and make sure to get rid of as much liquid as possible.
- Record the weight of the pellets.
- In total, the two pellets weighed 0.67 grams, which is lower yield than last time.
- Transfer pellet to one falcon tube.
- Resuspend in 5 ml/g of pellet Bug Buster (1x) by pipetting and gently vortexing.
- Put on shaker or rotating mixer for 15 min at RT.
- Take first fraction, F1 of this full cell lysate.
- Centrifuge 16000 g 20 min at 4 degrees C
- Take second fraction of this supernatant which should contain soluble proteins, while our desired protein should be in the pellet.
- Resuspend in the same volume of 1X Bugbuster as above.
- Make sure the pellet is completely resuspended!
- Take Fraction at this point (F2) Cell lysate #2
- Add DNAse (2 ul) and let rotate 20 min. (This may have been too much DNAse but it should be ok.)
- Add dry lysozyme to concentration of 200 ug / ml
- Dissolved the lysozyme in water and added the water.
- Let incubate on ice 30 minutes, swirl every 5 min.
- Take another fraction F3 here, to see if there is a difference after adding the DNAse and the lysozyme.
- Add 6 volumes of 1:10 diluted bugbuster (.1X)#*
- 6x3.4= 20.4 ml
- Can split up into two falcon tubes if necessary.
- Centrifuge 16000g 15 min. 4 degrees C to collect inclusion bodies.
- Collect supernatant as fraction S2. Inclusion body should be the pellet.
- Resuspend pellet in 1/2 volume of original 0.1X bug buster solution
- Mix to get an even suspension by pipetting and vortexing for several minutes and spin down as in step 9.
- Take supernatant fractions for each wash step.
- Repeat step 15-16 one more time.
- The BUgBuster manufacturer's protocol calls for two more times, but I the Honeybee paper does not mention multiple wash steps, and it seemed like we were losing a sizable portion of our product with each subsequent wash step.
- Resuspend inclusion body pellet in 3% SDS solution and incubate at 60 C in the water bath for 2 hours.
- Used 750 ul SDS.
- Store at 4C for further processing and analysis.