EThcD data of enolase (yeast, 46.8 kDa) was acquired in full profile mode (i.e. without noise thresholding) at a resolution setting of 240,000 at m/z 200 on a Thermo Orbitrap Eclipse mass spectrometer with 300 transient averages per spectrum and a precursor AGC target of 1e6. For this protein, a nanoelectrospray source was utilized, with a voltage of 2200 V applied to a fused silica emitter via a tee and platinum electrode. With fluoranthene as the reagent anion, enolase (52+, m/z 898) was subjected to 1.5 ms of ETD with a reagent AGC target of 2e6 and supplemented with collisional activation by HCD (15 NCE). Proton-transfer charge reduction (PTCR) using perfluoroperhydrophenanthrene (PFPP) as the reagent ion was performed on two fragment ion isolation windows, one spanning the m/z region lower than the precursor ion and one spanning the m/z region higher than the precursor ion using a reagent AGC target of 2e6 and a reaction times of 5-8 ms. PTCR reactions were used to disperse the fragment ions throughout the m/z domain, alleviating overlapping isotope distributions of some of the fragment ions in the more congested regions of the MS/MS spectra and mitigating spectral noise to improve the resulting spectral quality and fragment ion identifications.