Tm-edited DEER echo curves and Python fitting scripts for the paper entitled: "Measurement of an electron–methyl proton probability distance distribution in a protein using <i>T</i>_m-edited double electron-electron resonance EPR spectroscopy"

This deposition contains the full Tm-edited DEER dataset together with Python scripts for global fitting and analysis. Abstract of the paper: Pulsed double electron-electron resonance (DEER) EPR spectroscopy yields electron-electron distance probability distributions, P(ree), between the unpaired electrons of two paramagnetic spin labels. Here we show that phase memory time (Tm)-edited DEER can be used to measure electron-proton distance distributions in a methyl protonated, otherwise fully deuterated, protein spin-labeled with the rigid R1p nitroxide sidechain. This approach takes advantage of distance dependent nuclear spin-driven electron spin decoherence arising from intramolecular dipolar couplings between the unpaired electron on the spin label and neighboring (< 12 Å) methyl protons. Proof of principle is demonstrated using Staphylococus protein A in which one of the two nitroxide spin labels occupies two distinct regions of conformational space resulting in a bimodal electron-electron P(ree) distribution. One of the conformers is packed against the protein in close proximity to methyl protons while the other conformer is solvent exposed and far away (> 14 Å) from methyl protons. The dependence of the ratio of the intensities of the two peaks in the P(ree) distribution on the total evolution time T of the second echo period of the DEER experiment displays oscillations arising from dipolar electron-methyl proton couplings that can be described and analyzed using the same formalism as that used for determining electron-electron P(ree) distributions from DEER echo curves. Global fitting of a series of DEER echo curves acquired over a range of evolution times T allows one to extract an electron-methyl proton probability distance distribution, P(reH).