We study, with molecular dynamics simulations, a lysozyme protein immersed in a water-trehalose solution upon cooling. The aim is to understand the cryoprotectant role played by this disaccharide through the modifications that it induces on the slow dynamics of protein hydration water with its presence. The alpha -relaxation shows a fragile to strong crossover about 20 degrees higher than that in the bulk water phase and 15 degrees higher than that in lysozyme hydration water without trehalose. The protein hydration water without trehalose was found to show a second slower relaxation exhibiting a strong to strong crossover coupled with the protein dynamical transition. This slower relaxation time importantly appears enormously slowed down in our cryoprotectant solution. On the other hand, this long-relaxation in the presence of trehalose is also connected with a stronger damping of the protein structural fluctuations than that found when the protein is in contact with the pure hydration water. Therefore, this appears to be the mechanism through which trehalose manifests its cryoprotecting function.

Camisasca, G., De Marzio, M., Gallo, P. (2020). Effect of trehalose on protein cryoprotection: Insights into the mechanism of slowing down of hydration water. THE JOURNAL OF CHEMICAL PHYSICS, 153(22), 224503 [10.1063/5.0033526].

Effect of trehalose on protein cryoprotection: Insights into the mechanism of slowing down of hydration water

Camisasca, G;De Marzio, M;Gallo, P
2020

Abstract

We study, with molecular dynamics simulations, a lysozyme protein immersed in a water-trehalose solution upon cooling. The aim is to understand the cryoprotectant role played by this disaccharide through the modifications that it induces on the slow dynamics of protein hydration water with its presence. The alpha -relaxation shows a fragile to strong crossover about 20 degrees higher than that in the bulk water phase and 15 degrees higher than that in lysozyme hydration water without trehalose. The protein hydration water without trehalose was found to show a second slower relaxation exhibiting a strong to strong crossover coupled with the protein dynamical transition. This slower relaxation time importantly appears enormously slowed down in our cryoprotectant solution. On the other hand, this long-relaxation in the presence of trehalose is also connected with a stronger damping of the protein structural fluctuations than that found when the protein is in contact with the pure hydration water. Therefore, this appears to be the mechanism through which trehalose manifests its cryoprotecting function.
Camisasca, G., De Marzio, M., Gallo, P. (2020). Effect of trehalose on protein cryoprotection: Insights into the mechanism of slowing down of hydration water. THE JOURNAL OF CHEMICAL PHYSICS, 153(22), 224503 [10.1063/5.0033526].
File in questo prodotto:
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11590/384610
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 9
  • ???jsp.display-item.citation.isi??? 7
social impact