Re: Protein identification by molecular weight

Deb McMillen (mcmillen@morel.uoregon.edu)
Tue, 7 Jul 1998 12:12:57 -0700 (PDT)

Frances, Have you looked at the Protein Prospector programs at UCSF? I
use MS-Edman quite frequently to identify proteins that I have fragmented
(you can specify the type of digest that you have performed to get the
fragment) and then you can specify the molecular weight range of the
original protein. Just search on the Web for MS-Edman and you'll find
these programs.

Has your colleague tried to determine if the protein is glycosylated?
There are several simple de-glycosylation kits on the market now to
determine if the mass of the protein is solely due to amino acid sequence
or to glycosylation. And depending on the method of isolation of the
protein, is it a multimer (as one functional complex) or an aggregate
formed from several proteins? We routinely digest "large" proteins and
sequence several of the resulting peptides to only find that the one
protein is indeed 5 proteins migrating on the gel as if it were one unique
(and they are usually pretty excited about it) protein.

Hope this helps,
Deb McMillen
Institute of Molecular Biology
University of Oregon
EUgene OR

On Tue, 7 Jul 1998, Frances Finn wrote:

> Dear ABRFers
> A colleague has a very high molecular weight protein she wishes to
> identify. Are there any resources out there where one could search
> using molecular weight as a guide? I tried genbank and BLAST and didn't
> find anything but my perusal was not exhaustive and I may have missed
> something easy.
>
> Frances Finn
>