The thermodynamics of the electron transfer (ET) process for beef heart and yeast cytochromes c and the Lys72Ala/Lys73Ala/Lys79Ala mutant of the latter species subjected to progressive urea-induced unfolding was determined electrochemically. The results indicate the presence of at least three protein forms which were assigned to a low-temperature and a high-temperature His-Met intermediate species and a bis-histidinate form (although the presence of a His-Lys form cannot be excluded). The much lower E°’ value of the bis-histidinate conformer as compared to His-Met ligated species is largely determined by the enthalpic contribution induced by axial ligand substitution. The biphasic E°’ vs. T profile for the His-Met species is due to a difference in reduction entropy between the conformers at low and high temperatures. Enthalpy-entropy compensation phenomena for the reduction reaction at varying urea concentration for all the forms of the investigated cytochromes c were addressed and discussed

Redox Thermodynamics of cytochrome c subjected to urea induced unfolding / Monari, Stefano; Ranieri, Antonio; DI ROCCO, Giulia; G., van der Zwan; S., Peressini; C., Tavagnacco; D., Millo; Borsari, Marco. - In: JOURNAL OF APPLIED ELECTROCHEMISTRY. - ISSN 0021-891X. - STAMPA. - 39(2009), pp. 2181-2190.

I documenti presenti in Iris Unimore sono rilasciati con licenza Creative Commons Attribuzione - Non commerciale - Non opere derivate 3.0 Italia, salvo diversa indicazione.
In caso di violazione di copyright, contattare Supporto Iris

Powered by IRIS-about IRIS-Utilizzo dei cookie

 Copyright © 2021