Coherent X-ray Scattering Reveals Nanoscale Fluctuations in Hydrated ProteinsShow others and affiliations
2023 (English)In: Journal of Physical Chemistry B, ISSN 1520-6106, E-ISSN 1520-5207, Vol. 127, no 21, p. 4922-4930Article in journal (Refereed) Published
Abstract [en]
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 dynamics in the deeply supercooled regime (T = 180 K), which is typically not accessible through equilibrium methods. The observed stimulated dynamic response is attributed to collective stress-relaxation as the system transitions from a jammed granular state to an elastically driven regime. 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 normalized variance χT. The amplification of fluctuations is consistent with previous studies of hydrated proteins, which indicate the key role of density and enthalpy fluctuations in hydration water. Our study provides new insights into X-ray stimulated stress-relaxation and the underlying mechanisms behind spatiotemporal fluctuations in biological granular materials.
Place, publisher, year, edition, pages
American Chemical Society (ACS) , 2023. Vol. 127, no 21, p. 4922-4930
National Category
Physical Chemistry
Identifiers
URN: urn:nbn:se:kth:diva-336600DOI: 10.1021/acs.jpcb.3c02492ISI: 001014320500001PubMedID: 37209106Scopus ID: 2-s2.0-85160964770OAI: oai:DiVA.org:kth-336600DiVA, id: diva2:1797401
Funder
Swedish Research Council, 2019-05542Ragnar Söderbergs stiftelseGerman Research Foundation (DFG), 390715994German Research Foundation (DFG), EXC 2056 390715994Carl Tryggers foundation , CTS21:1589Wenner-Gren Foundations, UPD2021-0144
Note
QC 20230915
2023-09-142023-09-142023-09-15Bibliographically approved