Removal of internal peptides by biotinylation and streptavidin purification

Box: Removal of internal peptides by biotinylation and streptavidin purification

Taken from: Positional proteomics: preparation of amino-terminal peptides as a strategy for proteome simplification and characterization

Published in: Nature Protocols


The boxed method was originally published in Nature Methods in an article entitled "Positional proteomics: selective recovery and analysis of N-terminal proteolytic peptides".

One of the problems with looking at all of the proteins in a cell is that there are a lot of them! A further complication is that most methods of identifying the proteins by mass spectroscopy involve chopping them up into smaller pieces before HPLC separation. This protocol is a way to simplify this mixture by selectively isolating the "pieces" corresponding to the N-termini.