AbstractHigh‐resolution neutron time‐of‐flight (TOF) spectra were measured for partly deuterated hen egg‐white lysozyme in solution with and withoutN‐acetyl‐glucosamine inhibitor bound to the cleft, and in polycrystalline form. Weak but reproducible bands occur at frequencies between 25 and 375 cm−1. The bands were tentatively assigned on the basis of previous results for homopolypeptides. At very small energy transfers (between about 1 cm−1and 40 cm−1), the TOF spectra show a dependence both on inhibitor binding and crystalline environment. This is interpreted in terms of conformat