At low temperatures, proteins exist in a glassy state, a state that has no conformational flexibility and shows no biological functions. In a hydrated protein, at temperatures around 220 K, this flexibility is restored, and the protein is able to sample more conformational substates, thus becoming biologically functional. This ‘‘dynamical’’ transition of protein is believed to be triggered by its strong coupling with the hydration water, which also shows a similar dynamic transition. Here we demonstrate experimentally that this sudden switch in dynamic behavior of the hydration water on lysozyme occurs precisely at 220 K and can be described as a fragile-to-strong dynamic crossover. At the fragile-to-strong dynamic crossover, the structure of hydration water makes a transition from predominantly high-density (more fluid state) to low- density (less fluid state) forms derived from the existence of the second critical point at an elevated pressure.
Observation of Fragile-to-Strong Dynamic Crossover in Protein Hydration Water / S.-H. CHEN; L. LIU; E. FRATINI; P. BAGLIONI; A. FARAONE; E. MAMONTOV. - In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA. - ISSN 1091-6490. - STAMPA. - 104:(2006), pp. 9012-9016. [10.1073/pnas.0602474103]
Observation of Fragile-to-Strong Dynamic Crossover in Protein Hydration Water
FRATINI, EMILIANO;BAGLIONI, PIERO;
2006
Abstract
At low temperatures, proteins exist in a glassy state, a state that has no conformational flexibility and shows no biological functions. In a hydrated protein, at temperatures around 220 K, this flexibility is restored, and the protein is able to sample more conformational substates, thus becoming biologically functional. This ‘‘dynamical’’ transition of protein is believed to be triggered by its strong coupling with the hydration water, which also shows a similar dynamic transition. Here we demonstrate experimentally that this sudden switch in dynamic behavior of the hydration water on lysozyme occurs precisely at 220 K and can be described as a fragile-to-strong dynamic crossover. At the fragile-to-strong dynamic crossover, the structure of hydration water makes a transition from predominantly high-density (more fluid state) to low- density (less fluid state) forms derived from the existence of the second critical point at an elevated pressure.File | Dimensione | Formato | |
---|---|---|---|
2006PNAS_LYS.pdf
Accesso chiuso
Tipologia:
Versione finale referata (Postprint, Accepted manuscript)
Licenza:
Tutti i diritti riservati
Dimensione
1.04 MB
Formato
Adobe PDF
|
1.04 MB | Adobe PDF | Richiedi una copia |
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.