Uncovering dehydration in cytochrome c refolding from urea- and guanidine hydrochloride-denatured unfolded state by high pressure spectroscopy.

ABSTRACT: To investigate the dehydration associated with protein folding, the partial molar volume changes for protein unfolding (ΔV _u) in cytochrome c (Cyt c) were determined using high pressure absorption spectroscopy. ΔV _u values for the unfolding to urea- and guanidine hydrochloride (GdnHCl)-denatured Cyt c were estimated to be 56±5 and 29±1 mL mol^-1, respectively. Considering that the volume change for hydration of hydrophobic groups is positive and that Cyt c has a covalently bonded heme, a positive ΔV _u reflects the primary contribution of the hydration of heme. Because of the marked tendency of guanidium ions to interact with hydrophobic groups, a smaller number of water molecules were hydrated with

SUBMITTER: Konno S 

PROVIDER: S-EPMC6373425 | biostudies-literature | 2019

REPOSITORIES: biostudies-literature