Peptide quantification - (Feb/26/2016 )

Hello, so I have a vegetable protein extract which will undergo some tryptic digestion..prior to MS.
The thing is that I would love to be able to fractionate and quantify peptide ranges before any MS experiments.

I was wondering if size exclusion chromatography is the way to go? Could it separate peptides of <5aa from 15-25 e.g or is that too fine??
Also what would one do for standards?

Regards
John

It is common to run PAGE gels for proteins, slice them into fragments, and trypsin digest the sample in-gel before loading on a mass spec.

It should be easy to find detailed protocols for this process. The same technique is also used for 2-D gels, when picking spots.

Thank you. I appreciate your reply. That is not what I am trying to do. I am trying to fragment based on peptide size, post digest

fragmented peptides are usually separated by reversed phase hplc (and can be coupled with a mass spec).

you could separate by gel filtration (sec) if you have the right matrix and the fragments are in the right size range. ge lifesciences has a superdex peptide column for this purpose but you most likely won't get distinct peaks but, rather, ranges of size.

Thanks Me...a sound suggestion