biostudies-literatureFuller CNNIGMS NIH HHS13965-13973https://www.ebi.ac.uk/biostudies/studies/S-EPMC12312367biostudies-literatureUnknown97(26)Ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry (UHR FT-ICR MS) for top-down proteomics has shown the potential to resolve proteoforms and splice variants, particularly those with post-translational modifications. Here, we integrate trapped ion mobility and mass selection in tandem with ultraviolet photodissociation (UVPD) followed by FT-ICR MS measurements. The proposed method using mobility/mass-selected UVPD before FT-ICR MS allows for high protein sequence coverage and PTM localization with high mass accuracy (<1 ppm) and a better duty cycle (2×). When applied to the analysis of a bovine histone mixture, characteristic UVPD <i>a</i>/<i>b</i>/<i>c</i>/<i>x</i>/<i>y</i>/<i>z</i> ions led to the annotation of 51 proteoforms from H2B, H2A, and H4 core histAnalytical chemistryHistone Analysis Using Mobility- and Mass-Selected Ultraviolet Photodissociation in Tandem with Ultra-High-Resolution Mass Spectrometry.PMC12312367R35 GM153450Fuller CNKosmopoulou MJeanne Dit Fouque KValadares Tose LAlam MSFernandez-Lima FVan Orden SGarcia BASearfoss RMde Luna Vitorino FNRidgeway MESuckau DfalseHistone Analysis Using Mobility- and Mass-Selected Ultraviolet Photodissociation in Tandem with Ultra-High-Resolution Mass Spectrometry.Ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry (UHR FT-ICR MS) for top-down proteomics has shown the potential to resolve proteoforms and splice variants, particularly those with post-translational modifications. Here, we integrate trapped ion mobility and mass selection in tandem with ultraviolet photodissociation (UVPD) followed by FT-ICR MS measurements. The proposed method using mobility/mass-selected UVPD before FT-ICR MS allows for high protein sequence coverage and PTM localization with high mass accuracy (<1 ppm) and a better duty cycle (2×). When applied to the analysis of a bovine histone mixture, characteristic UVPD <i>a</i>/<i>b</i>/<i>c</i>/<i>x</i>/<i>y</i>/<i>z</i> ions led to the annotation of 51 proteoforms from H2B, H2A, and H4 core hist2025-01-01T00:00:00Z2025 Jul2026-03-18T13:31:41.622Z2025-08-18T09:54:19.408ZS-EPMC123123674055293910.1021/acs.analchem.5c02166