New protein footprinting: fast photochemical iodination combined with top-down and bottom-up mass spectrometry.

ABSTRACT: We report a new approach for the fast photochemical oxidation of proteins (FPOP) whereby iodine species are used as the modifying reagent. We generate the radicals by photolysis of iodobenzoic acid at 248 nm; the putative iodine radical then rapidly modifies the target protein. This iodine-radical labeling is sensitive, tunable, and site-specific, modifying only histidine and tyrosine residues in contrast to OH radicals that modify 14 amino-acid side chains. We iodinated myoglobin (Mb) and apomyoglobin (aMb) in their native states and analyzed the outcome by both top-down and bottom-up proteomic strategies. Top-down sequencing selects a certain level (addition of one I, two I's) of modification and determines the major components produced in the modification reaction, whereas bottom-up rev

SUBMITTER: Chen J 

PROVIDER: S-EPMC3630512 | biostudies-literature | 2012 Aug

REPOSITORIES: biostudies-literature