The Role of Salt in Mitochondria: Returning Cytochrome C to its Native State After Its Dissociation from Cardiolipin Containing Membranes

Pandiscia, Leah; Schweitzer‐Stenner, Reinhard

doi:10.1016/j.bpj.2013.11.2887

Cited by 3 publications

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“…We then restricted our attention to the protein cavity surrounding the heme group, which can be investigated by following the DMSO-induced changes in the CD spectra in the Soret region ( Figure 7 b). In fact, the optical activity in this spectral region depends on the coupling between electric dipole transition moments of π→π* transitions of the heme group and of the aromatic ring of Phe82 and is therefore affected by the interactions between the heme itself and its surroundings [ 27 , 76 , 80 , 81 , 82 , 83 , 84 ]. The CD spectrum of the M80A mutant in phosphate buffer differs from that of wt cytc in both the red shift of the maximum (406 vs. 400 nm) and in the absence of the minimum located between 415 and 420 nm which provides evidence for the substitution of axial ligand Met80 by the OH − ion [ 27 , 76 , 80 , 81 , 85 ].…”

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confidence: 99%

Assessing the Functional and Structural Stability of the Met80Ala Mutant of Cytochrome c in Dimethylsulfoxide

et al. 2022

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The Met80Ala variant of yeast cytochrome c is known to possess electrocatalytic properties that are absent in the wild type form and that make it a promising candidate for biocatalysis and biosensing. The versatility of an enzyme is enhanced by the stability in mixed aqueous/organic solvents that would allow poorly water-soluble substrates to be targeted. In this work, we have evaluated the effect of dimethylsulfoxide (DMSO) on the functionality of the Met80Ala cytochrome c mutant, by investigating the thermodynamics and kinetics of electron transfer in mixed water/DMSO solutions up to 50% DMSO v/v. In parallel, we have monitored spectroscopically the retention of the main structural features in the same medium, focusing on both the overall protein structure and the heme center. We found that the organic solvent exerts only minor effects on the redox and structural properties of the mutant mostly as a result of the modification of the dielectric constant of the solvent. This would warrant proper functionality of this variant also under these potentially hostile experimental conditions, that differ from the physiological milieu of cytochrome c.

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