Fast fluctuations in protein powders: The role of hydration

Comparative thermal unfolding study of psychrophilic and mesophilic subtilisin-like serine proteases by molecular dynamics simulations

“…In addition, increasing temperature will improve the mobility of the water molecules, which in turn facilitates collision between the water and the protein surface, thus resulting in improved flexibility of the protein (Sang et al, 2016;Vitkup et al, 2000). It has also been shown that the high protein hydration degree can impart sufficient mobility to proteins at low temperatures and that an increase in hydration degree can lower the glass transition temperature of proteins (Batzer & Kreibich, 1981;Paciaroni, Cinelli, Cornicchi, Francesco, & Onori, 2005). Therefore, it is reasonable to conclude that the observed more favorable protein-solvent interactions for VPR than for PRK, which arise from larger exposures of the polar area of VPR, are responsible for higher global structural flexibility of VPR.…”

Temperature dependence of fast fluctuations in single- and double-stranded DNA molecules: a neutron scattering investigation

“…The term A 0 (Q) is the elastic incoherent structure factor (EISF), the Qdependence of which provides information on the geometry of the investigated motions. Within the simple framework of the double-well model, already employed to describe the dynamics of proteins [15,16], the hydrogen atoms are considered dynamically equivalent and their motions are schematized as jumps between two distinct sites with a different free energy. The corresponding EISF is: …”

“…In the incoherent approximation the elastic intensity can be described by the following law [16,23]:…”

“…In the picosecond and nanosecond timescale, the dynamical behaviour of hydrated biopolymers is characterized by an onset of stochastic large-amplitude fluctuations taking place in the temperature range 200 -240 K [15][16][17][18][19][20][21]. In proteins [15][16][17][18], DNA [19,20] and tRNA [21], this dynamical transition has been supposed to be ruled by the hydration water, which would increase the structural flexibility of the biomolecule, by allowing the sampling of a large number of spatial conformations.…”

“…In proteins [15][16][17][18], DNA [19,20] and tRNA [21], this dynamical transition has been supposed to be ruled by the hydration water, which would increase the structural flexibility of the biomolecule, by allowing the sampling of a large number of spatial conformations. In addition, such a phenomenon has been also interpreted in terms of the Mode Coupling theory [15,19,20].…”