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

This dataset provides raw far-UV circular dichroism (CD) spectral files and a helicity summary table for two Clostridioides difficile–targeting endolysin catalytic domains, CD27L_EAD and PHICD111_20024_EAD. Spectra were recorded at 25 °C in 20 mM Tris buffer (pH 7.0) at 10 µM with 0–200 mM NaCl (0, 50, 100, 150, 200 mM) over 190–260 nm, using duplicate scans from two independent protein preparations per condition. Helicity values were estimated using BeStSel as described in the associated Data in Brief article, SDS-PAGE images are provided in the article figures and are not deposited here.