New MS-cleavable urea crosslinkers for proteomics

October 2018

Our team visited the conference „8th Symposium on Structural Proteomics“ that was held on 10-12th October in Berlin. One of the main topics of the conference was chemical crosslinking in structural elucidation of proteins using mass spectrometry.

Our main goal was to introduce the portfolio of our bioconjugation reagents, most notably the MS-cleavable lysine-reactive urea crosslinkers.

Besides the established C4-arm DSBU crosslinker (also termed as BuUrBu) developed by Prof. Dr. A. Sinz of the Martin Luther University in Halle, we presented the hitherto unreported shorter C3- and C2-arm urea crosslinkers.

One of the great advantages of the urea crosslinkers is that the presence of the central urea moiety which is prone to collision induced dissociation allows to unequivocally identify the crosslinks in tandem CID-MS experiments.

Another advantage of these crosslinkers is that the energy required for cleavage of the central urea unit lies approximately in the same region as the energy required to cleave the peptide bonds. Therefeore, this feature enables to simultaneously observe both the characteristic doublets arising from the central urea cleavage as well as the typical fragmentation patterns of the peptide backbone.

With this expanded palette of crosslinkers in hand, the proteomic researchers will be able to get a much deeper proteome XL-MS information than was previously possible.