Correlating solvation with conformational pathways of proteins in alcohol-water mixtures: a THz spectroscopic insight.
Phys Chem Chem Phys
; 23(32): 17536-17544, 2021 Aug 28.
Article
en En
| MEDLINE
| ID: mdl-34369530
ABSTRACT
Water, being an active participant in most of the biophysical processes, is important to trace how protein solvation changes as its conformation evolves in the presence of solutes or co-solvents. In this study, we investigate how the secondary structures of two diverse proteins - lysozyme and ß-lactoglobulin - change in the aqueous mixtures of two alcohols - ethanol and 2,2,2-trifluoroethanol (TFE) using circular dichroism measurements. We observe that these alcohols change the secondary structures of these proteins and the changes are protein-specific. Subsequently, we measure the collective solvation dynamics of these two proteins both in the absence and in the presence of alcohols by measuring the frequency-dependent absorption coefficient (α(ν)) in the THz (0.1-1.2 THz) frequency domain. The alcohol-water mixtures exhibit a non-ideal behaviour with the highest absorption difference (Δα) obtained at Xalcohol = 0.2. The protein solvation in the presence of the alcohols shows an oscillating behaviour in which Δαprotein changes with Xalcohol. Such an oscillatory behaviour of protein solvation results from a delicate interplay between the protein-water, protein-alcohol and water-alcohol associations. We attempt to correlate the various structural conformations of the proteins with the associated solvation.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Trifluoroetanol
/
Agua
/
Muramidasa
/
Etanol
/
Lactoglobulinas
Límite:
Animals
Idioma:
En
Revista:
Phys Chem Chem Phys
Asunto de la revista:
BIOFISICA
/
QUIMICA
Año:
2021
Tipo del documento:
Article
País de afiliación:
India