Top-down 193-nm ultraviolet photodissociation mass spectrometry for simultaneous determination of polyubiquitin chain length and topology.

ABSTRACT: Protein ubiquitin modifications present a vexing analytical challenge, because of the dynamic changes in the site of modification on the substrate, the number of ubiquitin moieties attached, and the diversity of linkage patterns in which they are attached. Presented here is a method to confidently assign size and linkage type of polyubiquitin modifications. The method combines intact mass measurement to determine the number of ubiquitin moieties in the chain with backbone fragmentation by 193-nm ultraviolet photodissociation (UVPD) to determine the linkage pattern. UVPD fragmentation of proteins leads to reproducible backbone cleavage at almost every inter-residue position, and in polyubiquitin chains, the N-terminally derived fragments from each constituent monomer are identical, up to th

SUBMITTER: Cannon JR 

PROVIDER: S-EPMC4318624 | biostudies-literature | 2015 Feb

REPOSITORIES: biostudies-literature