The influence of the Cys46/Cys55 disulfide bond on the redox and spectroscopic properties of human neuroglobin

Met80 and Tyr67 affect the chemical unfolding of yeast cytochromec: comparing the solutionvs.immobilized state

“…The former were converted to molar ellipticity [y] using the conversion factor [y] = y(deg)Á100/(dÁc), where c is the protein concentration (mol dm À3 ) and d is the thickness of the sample (path length, 0.5 cm), 21,84,90 while the latter were converted to De [M À1 cm À1 T À1 ] using the conversion factor De = y/(32 980ÁcÁdÁB), where c is the protein concentration, B is the magnetic field (1 T), and d is the thickness of the sample (path length, 0.5 cm). 13,[101][102][103][104] All experiments were carried out at 25 1C with protein solutions freshly prepared before use in 5 mM phosphate buffer pH 7 and the protein concentration was checked spectrophotometrically, using e 405 = 121 700 M À1 cm À1 for both the M80A and M80A/Y67A mutants. 105,106…”

“…Indeed, the E1 0 values of both variants in 6 M urea are similar to those determined for urea unfolded wt ycc and its K72A/K73A/ K79A mutant, 14 which were shown to possess His/His axial coordination. : 33,74,75,103,126,[128][129][130][131][132][133]135,138,139,145,146,148,149 The intrinsic enthalpic contribution depends on the donor properties of the axial heme ligands, the polarity and the electrostatics at the redox center, whereas the intrinsic entropic term is mainly controlled by oxidation-state dependent differences in the conformational degrees of freedom of the polypeptide chain. [74][75][76][77]98,99,103,126,[128][129][130][131][132][133]135,[137][138][139][144][145][146][147][148][149] For both variants, the E1 0 values increase linearly with increasing temperature with and without urea ( Fig.…”

“…The leastsquare fittings yield slopes of 1.23 and 2.40 and regression coefficients (r 2 ) of 0.999 and 0.995 for the M80A and M80A/ Y67A mutants, respectively. As the changes in DH 0 rc and DS 0 rc arising from the reduction-induced reorganization of the H-bond network at the protein-solvent interface (DH 0 rcðsolvÞ and DS 0 rcðsolvÞ ) are fully compensative, 20,34,74,75,103,104,[130][131][132][133]140,141,[146][147][148][149][150] the absence of perfect compensation (i.e. slopes greater than one) indicates that, beside solvent reorganization effects, protein-based ''intrinsic'' factors significantly contribute to the urea-induced changes in the reduction thermodynamics.…”

“…Downloaded on 10/29/2020 1:33:15 PM.This article is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported Licence. Fe 2+ reduction, determined by analyzing the temperature dependence of E1 0 14,[74][75][76][77]103,[109][110][111]. These thermodynamic data contain contributions from protein-based ''intrinsic'' factors DH 0 rcðintÞ ; DS 0…”

Electrochemical data on redox properties of human Cofilin-2 and its Mutant S3D

“…The data presented here are related to the research article [1] . These redox data are of use for determining the electron transfer properties of disulfide bridges in proteins [2] , [3] , [4] . Disulfide/thiol reactions are often critical in structural and conformational properties of proteins [5] .…”