10.1021/acs.jproteome.7b00043.s004 Timothy P. Cleland Timothy P. Cleland Caroline J. DeHart Caroline J. DeHart Ryan T. Fellers Ryan T. Fellers Alexandra J. VanNispen Alexandra J. VanNispen Joseph B. Greer Joseph B. Greer Richard D. LeDuc Richard D. LeDuc W. Ryan Parker W. Ryan Parker Paul M. Thomas Paul M. Thomas Neil L. Kelleher Neil L. Kelleher Jennifer S. Brodbelt Jennifer S. Brodbelt High-Throughput Analysis of Intact Human Proteins Using UVPD and HCD on an Orbitrap Mass Spectrometer American Chemical Society 2017 elucidate proteoform variation UVPD PTM high-throughput top-down analysis Intact Human Proteins Orbitrap Mass Spectrometer HCD data sets HeLa whole-cell lysate protein sequence coverage energy collisional dissociation 2017-04-17 00:00:00 Dataset https://acs.figshare.com/articles/dataset/High-Throughput_Analysis_of_Intact_Human_Proteins_Using_UVPD_and_HCD_on_an_Orbitrap_Mass_Spectrometer/4888649 The analysis of intact proteins (top-down strategy) by mass spectrometry has great potential to elucidate proteoform variation, including patterns of post-translational modifications (PTMs), which may not be discernible by analysis of peptides alone (bottom-up approach). To maximize sequence coverage and localization of PTMs, various fragmentation modes have been developed to produce fragment ions from deep within intact proteins. Ultraviolet photodissociation (UVPD) has recently been shown to produce high sequence coverage and PTM retention on a variety of proteins, with increasing evidence of efficacy on a chromatographic time scale. However, utilization of UVPD for high-throughput top-down analysis to date has been limited by bioinformatics. Here we detected 153 proteins and 489 proteoforms using UVPD and 271 proteins and 982 proteoforms using higher energy collisional dissociation (HCD) in a comparative analysis of HeLa whole-cell lysate by qualitative top-down proteomics. Of the total detected proteoforms, 286 overlapped between the UVPD and HCD data sets, with 68% of proteoforms having <i>C</i> scores greater than 40 for UVPD and 63% for HCD. The average sequence coverage (28 ± 20% for UVPD versus 17 ± 8% for HCD, <i>p</i> < 0.0001) was found to be higher for UVPD than HCD and with a trend toward improvement in <i>q</i> value for the UVPD data set. This study demonstrates the complementarity of UVPD and HCD for more extensive protein profiling and proteoform characterization.