4 replies to this topic

[cellgene]

When I load a cell lysate on a gel and do western blot against my protein of interest, I see a band at the right size(56kDa) and another that's about 10kDa lower.

When I perform an siRNA knockdown the lower band also disappears.

I know many modifications causing an upshift, but what can be causing any downshifts?

Thanks for the suggestions in advance

[bob1]

Potentially cleavage of a fragment.

[Inmost sun]

cellgene, on Apr 25 2010, 08:20 PM, said:

When I load a cell lysate on a gel and do western blot against my protein of interest, I see a band at the right size(56kDa) and another that's about 10kDa lower.

When I perform an siRNA knockdown the lower band also disappears.

I know many modifications causing an upshift, but what can be causing any downshifts?

Thanks for the suggestions in advance

proteolysis or splice variation or loss of posttranslational modifications

[cellgene]

thank you
i couldn't find any cleavage sites bioinformatically- but of course it still can be

So no modification causes the protein to run lower?

[mdfenko]

cellgene, on May 5 2010, 08:37 AM, said:

thank you
i couldn't find any cleavage sites bioinformatically- but of course it still can be

So no modification causes the protein to run lower?

an example, carboxypeptidases will remove one amino acid at a time, no specific cleavage site other than it be the carboxy terminus.

cleavage can be a ptm.