It happen to me too. My protein is 26 kDa, and walking in the SDS-PAGE
as 31 kDa protein, it is very interesting. any reason for that? may be
even in the denatured form, it takes sort of folding which gives rise
to bigger radius to protein than what we expect as a radius of
protein, it is getting slow down. I am not really sure, this is my
miaoqf at sina.com wrote in message news:<20040209144331.31153.qmail at ww02.hostica.com>...
> I expressed a protein in E.coli sucessfully and the DNA sequence is right. The theoretical MW is 25KD. But after its purification, the MW is 29-30KD in a reducing-SDS PAGE. More surprised me is the MW is 25KD when I run it in a non-reducing SDS pAGE. I don't know the reason. Who can help me ?