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Fluoroalcohol-induced structural changes of proteins: some aspects of cosolvent-protein interactions

Item Type:Article
Title:Fluoroalcohol-induced structural changes of proteins: some aspects of cosolvent-protein interactions
Creators Name:Gast, K. and Siemer, A. and Zirwer, D. and Damaschun, G.
Abstract:The conformational transitions of bovine β-lactoglobulin A and phosphoglycerate kinase from yeast induced by hexafluoroisopropanol (HFIP) and trifluoroethanol (TFE) have been studied by dynamic light scattering and circular dichroism spectroscopy in order to elucidate the potential of fluoroalcohols to bring about structural changes of proteins. Moreover, pure fluoroalcohol-water mixed solvents were investigated to prove the relation between cluster formation and the effects on proteins. The results demonstrate that cluster formation is mostly an accompanying phenomenon because important structural changes of the proteins occur well below the critical concentration of fluoroalcohol at which the formation of clusters sets in. According to our light scattering experiments, the remarkable potential of HFIP is a consequence of extensive preferential binding. Surprisingly, preferential binding seems to play a vanishing role in the case of TFE. However, the comparable Stokes radii of both proteins in the highly helical state induced by either HFIP or TFE point to a similar degree of solvation in both mixed solvents. This shows that direct binding or an indirect mechanism must be equally taken into consideration to explain the effects of alcohols on proteins. The existence of a compact helical intermediate with non-native secondary structure on the transition of β-lactoglobulin A from the native to the highly helical state is clearly demonstrated.
Keywords:Circular Dichroism, Hexafluoroisopropanol, Light Scattering, Protein Folding, Trifluoroethanol, Animals
Source:European Biophysics Journal with Biophysics Letters
Page Range:273-283
Date:1 January 2001
Official Publication:https://doi.org/10.1007/s002490100148
PubMed:View item in PubMed

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