Protein Identification

[lgbell at liverpool.ac.uk]

Gene S. Hall wrote:
> 
> What is the basic way to absolutely determine an unknown protein?  We
> are using SEC to separate human proteins from plasma.  How can we
> absolutely determine the molecular weight of these proteins and identify
> them.
> Thanks for your help,
> Gene
> 
> --
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
> Prof. Gene S. Hall, Analytical Chemist  Phone: 908-445-2590
> ICPMS Laboratory                        FAX:   908-445-5312
> Department of Chemistry
> Rutgers, The State University of New Jersey
> New Brunswick, NJ  08903
> %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%Mass spec, electrospray or MALDITOF of the isolated and purified protein 
would identify the mass.

As for the identity of the protein, mass spec of  selected protease 
digests produce a 'finger print' trace. This can be compared to the mass 
spec profile of the protease digestion products of known proteins and 
hence the unknown protein identified. I beleive there are programs 
available to carry out this mapping exercise.

Hope this helps,
Len Bell
lgbell at liv.ac.uk