Inelastic incoherent neutron scattering in some proteins

Inelastic incoherent neutron scattering in hen egg white lysozyme, alpha-chymotrypsin from bovine pancreas, and human serum albumin has been investigated. The effect of the isotopic hydrogen-deuterium exchange on the vibrational spectrum of lysozyme has been studied by analyzing the experimentally obtained density of states (DOS). Phonon and fracton regimes have been identified in the low-frequency region of the DOS of deuterated lysozyme. It has been shown that deuteration of lysozyme does not lead to significant changes in the phonon and fracton dimensions. At the same time, the most pronounced differences in G(omega) of deuterated and protonated lysozyme were identified at frequencies above 100 cm(-1). The DOS of alpha-chymotrypsin from bovine pancreas and human serum albumin at 285 K have been determined.