I have a protein which does NOT have any cysteine. I know that it does form oligomeric structures and I hypothesised the complexes formed through non covalent bonds.
If I boil the sampIe and add a reducing agent into the loading buffer I get just one band (monomeric form).
If I run a non-reducing SDS-page gel using a sample loading buffer without beta-mercaptoethanol, I get several bands (corresponding to dimers and trimers sizes).
I knew that the difference between the two type of gels was that in the non-reducing gel the disulfide bonds are not destroyed so, if there are oligomeric structures, you can detect them.
But I don't have any cysteine and I thought boiling can destroy non-covalent bonds.
So, I did expect not to see any difference.
The question is: why I did get several bands in my non reducing gel even after boiling the samples at 95 C for 5 min?
Does anyone has any experience in this field and is willing to help?
I would really appreciate cause it's the first time I'm trying to address a similar question and I'm kind of lost.
Thank you in advance