jp7b03888_si_001.pdf (292.69 kB)
Configurational Disorder of Water Hydrogen-Bond Network at the Protein Dynamical Transition
journal contribution
posted on 2017-06-21, 00:00 authored by Obaidur Rahaman, Maria Kalimeri, Marina Katava, Alessandro Paciaroni, Fabio SterponeWe introduce a novel
strategy to quantify the disorder of extended
water–water hydrogen-bond (HB) networks sampled in particle-based
computer simulations. The method relies on the conformational clustering
of the HB connectivity states. We successfully applied it to unveil
the fine relationship among the protein dynamical transition in hydrated
powder, which marks the activation of protein flexibility at Td ≈ 240 K, and the sudden increase in
the configurational disorder of the water HB network enveloping the
proteins. Our finding links, in the spirit of the Adam–Gibbs
relationship, the diffusivity of protein atoms, as quantified by the
hydrogen mean-square displacements, and the thermodynamic solvent
configurational entropy.