Richard M Searfoss | Search PubMed

PubMed2026

Comprehensive mass spectrometry screening-derived atlas of HDAC inhibitors reveals histone-specific acetylation changes.

Histone deacetylase inhibitors (HDACis) have emerged as valuable therapeutics for cancer and other diseases; however, their effects on histone post-translational modification remain poorly characterized. Here, we applied quantitative mass spectrometry and high-throughput sequencing to systematically profile site-specific changes in histone modifications in response to a panel of HDACis. This platform enabled mapping of histone modification changes across hundreds of sites, including low-abundance histone marks. Furthermore, an integrative analysis of chromatin immunoprecipitation followed by sequencing (ChIP-seq) and RNA-sequencing (RNA-seq) data identified genome-wide binding sites for the low-abundance histone modification of H2A.Z acetylation in HeLa and MDA-MB-231 breast cancer cells, highlighting the role of H2A.Z acetylation in regulating gene expression across diverse biological pathways, including specific genes involved in tumor suppressor pathways. Our findings provide a functional resource for identifying and quantifying histone modification changes and transcriptional regulation of histone H2A.Z acetylation following pharmacological perturbation.

Histone Deacetylase Inhibitors↗

PubMed2025

Establishing a Top-Down Proteomics Platform on a Time-of-Flight Instrument with Electron-Activated Dissociation.

Top-down proteomics is the study of intact proteins and their post-translational modifications with mass spectrometry. Historically, this field is more challenging than its bottom-up counterpart because the species are much bigger and have a larger number of possible combinations of sequences and modifications; thus, there is a great need for technological development. With improvements in instrumentation and a multiplicity of fragmentation modes available, top-down proteomics is quickly gaining in popularity with renewed attention on increasing confidence in identification and quantification. Here, we systematically evaluated the Sciex ZenoTOF 7600 system for top-down proteomics, applying standards in the field to validate the platform and further experimenting with its capabilities in electron-activated dissociation and post-translational modification site localization. The instrument demonstrated robustness in standard proteins for platform QC, as aided by zeno trapping. We were also able to apply this to histone post-translational modifications, achieving high sequence coverage that allowed PTM's site localization across protein sequences with optimized EAD fragmentation. We demonstrated the ability to analyze proteins spanning the mass range and included analysis of glycosylated proteins. This is a reference point for future top-down proteomics experiments to be conducted on the ZenoTOF 7600 system.

Proteomics↗