identification of major protein; public 2D/mass-spec databases? - (Jan/19/2014 )

in my total cell lysates (at least, of 293T and HeLa cells), after Ponceau staining I always see the band at 80 kDa (see picture attached). Its intensity stably corresponds to loading and is not changed upon different treatments (starvation, transfections etc.), so I am just curious if it could be used as an alternative loading control. I guess that people who routinely do many 2D/mass-spec runs probably identified this protein in their samples already - are there any public databases or repositories where such data can be found?

I don't know the identity, but there is a good chance that the band is made up of multiple proteins.  High abundance proteins are often cyto-skeletal.

bob1 on Sun Jan 19 09:17:02 2014 said:

I don't know the identity, but there is a good chance that the band is made up of multiple proteins.  High abundance proteins are often cyto-skeletal.

well, I know that there are also many non-cytoskeletal proteins giving very strong bands/spots (e.g., Cyclophilin A, chaperonin 60, etc). But it seems indeed that in my case it is probably made of multiple proteins (alas): on the publicly available 2D pictures of HeLa lysate, I don't see any major spot of this size.