Biology subjects

Kolbowski, L.

Publications and source records attributed to Kolbowski, L..

5 recordsLinked to original sources

bioRxiv2025

Assessment of Reported Error Rates in Crosslinking Mass Spectrometry

We benchmarked eight software tools in crosslinking mass spectrometry (MS) to evaluate their accuracy in detecting protein-protein interactions. Whereas about half performed reliably, others reported up to 31-fold more false interactions than indicated by their reported false discovery rates. During this community-driven effort, we helped correct one of the poorer-performing tools. Our findings demonstrate that, with robust algorithms, crosslinking MS can deliver highly dependable insights into biological systems.

bioinformatics↗

bioRxiv2023

Cleavable crosslinkers redefined by novel MS3-trigger algorithm

Crosslinking MS is currently transitioning from a routine tool in structural biology to enabling structural systems biology. MS-cleavable crosslinkers could substantially reduce the associated search space expansion by allowing an MS3-based approach for identifying crosslinked peptides. However, MS2-based approaches currently outperform approaches utilising MS3. We show here that MS3-trigger sensitivity and specificity were hampered algorithmically. Our four-step MS3-trigger algorithm greatly outperformed currently employed methods and comes close to reaching the theoretical limit.

bioinformatics↗

bioRxiv2021

Improved peptide backbone fragmentation is the primary advantage of MS-cleavable crosslinkers

Proteome-wide crosslinking mass spectrometry studies have coincided with the advent of MS-cleavable crosslinkers that can reveal the individual masses of the two crosslinked peptides. However, recently such studies have also been published with non-cleavable crosslinkers suggesting that MS-cleavability is not essential. We therefore examined in detail the advantages and disadvantages of using the most popular MS-cleavable crosslinker, DSSO. Indeed, DSSO gave rise to signature peptide fragments with a distinct mass difference (doublet) for nearly all identified crosslinked peptides. Surprisingly, we could show that it was not these peptide masses that proved the main advantage of MS-cleavability of the crosslinker, but improved peptide backbone fragmentation that allowed for more confident peptide identification. We also show that the more intricate MS3-based data acquisition approaches lack sensitivity and specificity, causing them to be outperformed by the simpler and faster stepped HCD method. This understanding will guide future developments and applications of proteome-wide crosslinking mass spectrometry.

systems biology↗

bioRxiv2020

Ultraviolet Photodissociation of tryptic peptide backbones at 213 nm

We analyzed the backbone fragmentation behavior of tryptic peptides of a four protein mixture and of E. coli lysate subjected to Ultraviolet Photodissociation (UVPD) at 213 nm on a commercially available UVPD-equipped tribrid mass spectrometer. We obtained 15,178 high-confidence peptide-spectrum matches by additionally recording a reference beam-type collision-induced dissociation (HCD) spectrum of each precursor. Type a, b and y ions were most prominent in UVPD spectra and median sequence coverage ranged from 5.8% (at 5 ms laser excitation time) to 45.0% (at 100 ms). Overall sequence fragment intensity remained relatively low (median: 0.4% (5 ms) to 16.8% (100 ms) of total intensity) and remaining precursor intensity high. Sequence coverage and sequence fragment intensity ratio correlated with precursor charge density, suggesting that UVPD at 213 nm may suffer from newly formed fragments sticking together due to non-covalent interactions. UVPD fragmentation efficiency therefore might benefit from supplemental activation, as was shown for ETD. Aromatic amino acids, most prominently tryptophan, facilitated UVPD. This points at aromatic tags as possible enhancers of UVPD. Data are available via ProteomeXchange with identifier PXD018176 and on spectrumviewer.org/db/UVPD_213nm_trypPep.

systems biology↗

bioRxiv2019

xiView: A common platform for the downstream analysis of Crosslinking Mass Spectrometry data

xiView provides a common platform for the downstream analysis and visualisation of Crosslinking Mass Spectrometry data. It is independent of the search software used and its input is compliant with the relevant mass spectrometry data standards. It uses established visualisation techniques, notably Multiple Coordinated Views, to help the user explore the data and is designed to facilitate comparisons between different datasets.

molecular biology↗