Alexey Nesvizhskii

@nesvilab.bsky.social

Godfrey D. Stobbe Professor of Bioinformatics at U of Michigan. Trained as a theoretical physicist, now focusing on proteomics and proteogenomics. https://fragpipe.nesvilab.org/

A Chemical Proteomics Method to Quantify Cysteine S-Acylation | ACS Chemical Biology pubs.acs.org/doi/abs/10.1...

A Chemical Proteomics Method to Quantify Cysteine S-Acylation

S-acylation, often referred to as S-palmitoylation, is a reversible and dynamic posttranslational modification that corresponds to the addition of a long-chain fatty acid to cysteine (Cys) residues. Established mass spectrometry-based chemoproteomics methods have improved our understanding of the S-acylation proteome, notably by identifying hundreds of S-acylated proteins, sometimes with the modified Cys. However, the precise quantification of S-acylation levels for each Cys within a single sample remains challenging at the proteome level. Quantification of S-acylation levels is critical to further our understanding of protein S-acylation in cellular function and its role in health and diseases. We report here the development of an S-acylation quantification workflow based on the sequential labeling of free Cys and S-acylated Cys with isotopic labeling reagents. The workflow was extensively optimized, notably by comparing the number of sites identified with two alkyne-tagged Cys-reactive isotopic probes and four azido-tagged biotin-based capture reagents. By integrating this enhanced workflow with high-field asymmetric waveform ion mobility spectrometry (FAIMS) on LC–MS/MS instruments for the separation of labeled peptides, over 17,000 unique Cys could be quantified in biological samples. Application of the S-acylation quantification workflow to cellular proteomes allowed for the quantification of S-acylation levels in a HeLa proteome. We also identified dynamic S-acylation changes in response to autophagy induction.

pubs.acs.org

So glad to see this online today! With FragPipe and the many other Koina APIs, we wanted to democratize deep learning, especially for those without access to expensive GPUs. Major kudos to my co first author Ludwig for setting up the server. I encourage ML developers to put their models on Koina

Ludwig Lautenbacher@llautenbacher.bsky.social · 9mo ago

Exited to share our latest work! Out now in @natcomms.nature.com Koina aims to transform how #proteomics uses machine learning. You no longer need to be a tech wizard to use ML and now can easily run #ML models. Integrated with FragPipe, Skyline and EncyclopeDIA! www.nature.com/articles/s41...

How can we study target engagement and selectivity of covalent inhibitors? Which electrophilic probes are best suited to study a certain amino acid? Our study on "Profiling the proteome-wide selectivity of diverse electrophiles" is published in Nature Chemistry.(1/7) www.nature.com/articles/s41...

Profiling the proteome-wide selectivity of diverse electrophiles - Nature Chemistry

Covalent inhibitors are powerful entities in drug discovery. Now the amino acid selectivity and reactivity of a diverse electrophile library have been assessed proteome-wide using an unbiased workflow...

nature.com

The University of Michigan now blocks the iProX database, which is a part of the PRIDE consortium of mass spec data repositories. All requests to unblock were denied. Any other US universities in a similar situation? There is a lot of valuable MS proteomics data there no longer accessible to us.

It was a great pleasure to teach #FragPipe at the Biological Proteomics for Beginners workshop at #UCSD, sponsored by Thermo Fisher Scientific. We had a fantastic group of grad students, postdocs, and professors. Yes, I even got to teach UCSD professors how to analyze bottom-up proteomics data 😁

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New preprint: We isolate peptide–RNA photo-crosslinks with tunable RNA chains from living cells for mass spec. This maps over 4,700 crosslinking sites across 744 proteins and offers the first glimpse into the RNA sequences in crosslinks by MS. Read here: doi.org/10.1101/2025...

Peptide-RNA photo-crosslinks with tunable RNA chain map protein-RNA interfaces

Photo-crosslinking mass spectrometry enables the identification of protein-RNA interactions in living cells, pinpointing interaction interfaces at single-amino acid resolution. However, current isolat...

doi.org

It's now properly published. If you want to easily check important characteristics of your data before diving into complicated statistics, check out PSManalyst. PSManalyst: A Dashboard for Visual Quality Control of FragPipe Results | Journal of Proteome Research pubs.acs.org/doi/10.1021/...

PSManalyst: A Dashboard for Visual Quality Control of FragPipe Results

FragPipe is recognized as one of the fastest computational platforms in proteomics, making it a practical solution for the rapid quality control of high-throughput sample analyses. Starting with version 23.0, FragPipe introduced the “Generate Summary Report” feature, offering .pdf reports with essential quality control metrics to address the challenge of intuitively assessing large-scale proteomics data. While traditional spreadsheet formats (e.g., tsv files) are accessible, the complexity of the data often limits user-friendly interpretation. To further enhance accessibility, PSManalyst, a Shiny-based R application, was developed to process FragPipe output files (psm.tsv, protein.tsv, and combined_protein.tsv) and provide interactive, code-free data visualization. Users can filter peptide-spectrum matches (PSMs) by quality scores, visualize protease cleavage fingerprints as heatmaps and SeqLogos, and access a range of quality control metrics and representations such as peptide length distributions, ion densities, mass errors, and wordclouds for overrepresented peptides. The tool facilitates seamless switching between PSM and protein data visualization, offering insights into protein abundance discrepancies, samplewise similarity metrics, protein coverage, and contaminants evaluation. PSManalyst leverages several R libraries (lsa, vegan, ggfortify, ggseqlogo, wordcloud2, tidyverse, ggpointdensity, and plotly) and runs on Windows, MacOS, and Linux, requiring only a local R setup and an IDE. The app is available at (https://github.com/41ison/PSManalyst.

pubs.acs.org

Wow, a record breaking number of the Nesvizhskii lab members attending #ASMS2025! 9 posters, 3 evening workshops, and one Bioinformatics Hub on #FragPipe. Plus multiple collaborative posters with other groups. See you in Baltimore! PS. Below is our recent group photo, including all those attending

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The power of #MSFragger open search! “we applied the mass-tolerant search engine MSfragger and found that phosphorylation as well as ubiquitination were well preserved after XDNAX. To our great interest, we found an additional modification of 321 Da occurring only in the irradiated SILAC channel”

Kusterlab@kusterlab.bsky.social · last yr.

🚨Our new paper is online🚨 We use zero-distance⚡photo-crosslinking⚡to reveal direct protein-DNA interactions in living cells, enabling quantitative analysis of the DNA-interacting proteome on a timescale of minutes. #DNA #Chromatin #Proteomics www.cell.com/cell/fulltex...