Coherent X-ray Scattering Reveals Nanoscale Fluctuations in Hydrated Proteins
Abstract
Hydrated proteins undergo a transition in the deeply supercooled regime, which is attributed to rapid changes in hydration water and protein structural dynamics. Here, we investigate the nanoscale stress relaxation in hydrated lysozyme proteins stimulated and probed by X-ray Photon Correlation Spectroscopy (XPCS). This approach allows us to access the nanoscale dynamic response in the deeply supercooled regime (T = 180 K) which is typically not accessible through equilibrium methods. The relaxation time constants exhibit Arrhenius temperature dependence upon cooling with a minimum in the Kohlrausch-Williams-Watts exponent at T = 227 K. The observed minimum is attributed to an increase in dynamical heterogeneity, which coincides with enhanced fluctuations observed in the two-time correlation functions and a maximum in the dynamic susceptibility quantified by the normalised variance . Our study provides new insights into X-ray stimulated stress relaxation and the underlying mechanisms behind spatio-temporal fluctuations in biological granular materials.
Keywords
Cite
@article{arxiv.2301.11043,
title = {Coherent X-ray Scattering Reveals Nanoscale Fluctuations in Hydrated Proteins},
author = {Maddalena Bin and Mario Reiser and Mariia Filianina and Sharon Berkowicz and Sudipta Das and Sonja Timmermann and Wojciech Roseker and Robert Bauer and Jonatan Öström and Aigerim Karina and Katrin Amann-Winkel and Marjorie Ladd-Parada and Fabian Westermeier and Michael Sprung and Johannes Möller and Felix Lehmkühler and Christian Gutt and Fivos Perakis},
journal= {arXiv preprint arXiv:2301.11043},
year = {2024}
}