Far-UV circular dichroism datasets describing salt dependent secondary structure of Clostridioides difficile endolysin catalytic domains

This dataset contains far-UV circular dichroism data for the enzymatically active domains of two Clostridioides difficile–targeting bacteriophage endolysins, CD27L_EAD and PHICD111_20024_EAD. Measurements were performed at 25 °C using 10 µM protein in 20 mM Tris-HCl buffer (pH 7.0) containing 0, 50, 100, 150, or 200 mM NaF in a 0.5 mm path length cuvette. For each protein and NaF condition, three consecutive scans of the same sample were acquired. The dataset includes instrument-exported raw circular dichroism spectra (.csv), averaged spectra (.csv), high-tension signal traces (.csv), buffer blank spectra (.csv), processed mean residue ellipticity datasets (.xlsx), CDPro/CDSSTR output files (.out), and a summary table of α-helical content (.xlsx). CDPro analysis was performed using the CDSSTR algorithm with the SP43 reference set over 195–240 nm.