Thiol-exchange in DTSSP crosslinked peptides is proportional to cysteine content and precisely controlled in crosslink detection by two-step LC-MALDI MSMS.

ABSTRACT: The lysine-specific crosslinker 3,3'-dithiobis(sulfosuccinimidylpropionate) (DTSSP) is commonly used in the structural characterization of proteins by chemical crosslinking and mass spectrometry and we here describe an efficient two-step LC-MALDI-TOF/TOF procedure to detect crosslinked peptides. First MS data are acquired, and the properties of isotope-labeled DTSSP are used in data analysis to identify candidate crosslinks. MSMS data are then acquired for a restricted number of precursor ions per spot for final crosslink identification. We show that the thiol-catalyzed exchange between crosslinked peptides, which is due to the disulfide bond in DTSSP and known to possibly obscure data, can be precisely quantified using isotope-labeled DTSSP. Crosslinked peptides are recognized as 8 Da dou

SUBMITTER: Lambert W 

PROVIDER: S-EPMC3218361 | biostudies-literature | 2011 Oct

REPOSITORIES: biostudies-literature