Protein degradation - (Mar/18/2009 )
Dear all,
I have yet another problem with the protein I am purifying, I have tested the quality and amount of purification on SDS-PAGE followed by coommassie staining, there was a very nice and clear band, it was a month ago. Today I have done SDS-PAGE and coommassie again and the same band of the same protein and the same amount of the protein is barely seen! Therefore I have concluded that the protein was partially degraded. I keep it at 4 C, since it looses activity if frozen, I sterilize it with 0.2 uM filter.
Is there something I can do in order to prevent protein degradation? Add glycerol? Increase salt concentration?
Thank you very much in advance.
MariaG on Mar 18 2009, 06:19 AM said:
I have yet another problem with the protein I am purifying, I have tested the quality and amount of purification on SDS-PAGE followed by coommassie staining, there was a very nice and clear band, it was a month ago. Today I have done SDS-PAGE and coommassie again and the same band of the same protein and the same amount of the protein is barely seen! Therefore I have concluded that the protein was partially degraded. I keep it at 4 C, since it looses activity if frozen, I sterilize it with 0.2 uM filter.
Is there something I can do in order to prevent protein degradation? Add glycerol? Increase salt concentration?
Thank you very much in advance.
What about proteases inhitibors?
if you can't freeze it then you can try adding glycerol to about 50% and then store at -20C. it won't freeze but should survive longer.