Abstract
The reduction of acetylated, fully succinylated and dicarboxymethyl horse cytochromes c by the radicals CH 3CH(OH), CO ⨥ 2, O ⨥ 2, and e − aq′ and the oxidation of the reduced cytochrome c derivatives by Fe(CN) 3− 6 were studied using the pulse radiolysis technique. Many of the reactions were also examined as a function of ionic strength. By obtaining rate constants for the reactions of differently charged small molecules redox agents with the differently charged cytochrome c derivatives at both zero ionic strength and infinite ionic strength, electrostatic and conformational contributions to the electron transfer mechanism were effectively partitioned from each other in some cases. In regard to cytochrome c electron transfer mechanism, the results, especially those for which conformational influences predominate, are supportive of the electron being transferred in the heme edge region.
Highlights
In order to understand the mechanism of electron transfer of the cytochromes c, the relationship between their structure and function·have to be thoroughly studied
I Ji which conformational influences predominate, are supportive of the electron being transferred in the heme edge region
In situ according to the reactions that are presented in Table 2- using .2 appropriate concentrations of reagents
Summary
In order to understand the mechanism of electron transfer of the cytochromes c, the relationship between their structure and function·have to be thoroughly studied. One important approach to this problem is the use of chemical derivatives of the protein [1] In this approach the effect of chemical modification of specific amino acid residues upon the conformation, net charge, and reactivity of the protein are important to consider. In some derivatives of cytochrome c the modification does not change the overall conformation of the protein, as can be judged from the intact physicochemical properties of these molecules [2], whereas in other cases the native conformation is significantly changed [1]. In the case of acetylated cytochrome c (ACC), the conformation of the protein is only slightly perturbed [1], as indicated by the minor changes in the physico-chemical properties of this derivatiye. In the case of succinylated cytochrome c (SUCC), the conformation of the protein is much more disrupted and open than that of the native protein and the 695 nm band is lost
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Biochimica et Biophysica Acta (BBA) - Bioenergetics
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
