Please help: A proteolyzed product running bigger on an SDS gel?
I'm trying to get to the bottom of a claim in my lab that a breakdown
product of our favorite protein actually runs at a HIGHER molecular
weight than the full-length product on a 10% SDS gel.
The breakdown product is supposedly 13 residues shorter at the C-terminus.
Our protein is:
-12.7 KD protein,
-very basic (with a PI of 9.42)
-supposedly unstructured in the absence of its specific RNA ligand
(not generally present within E.coli)
Our protein runs at around 13-14 KD, and the supposed breakdown
product at 15KD
For those of you interested, the full-length protein sequence can be
found at :
[Only registered users see links. ]
(note first two residues, ML, represent a false start, and the NTD
methionine is cleaved in vivo, thus the length of the protein is
actually 108 AA)
Please , I'd appreciate it if anyone who can help me to understand an
explanation for this claim