Rate of oxidative modification of cytochrome c by hydrogen peroxide is modulated by Hofmeister anions

15Citations
Citations of this article
10Readers
Mendeley users who have this article in their library.

Abstract

Cytochrome c (cyt c) and other heme proteins are oxidatively modified in the presence of hydrogen peroxide in a concentration- and time-dependent manner. Cyt c modification has been monitored by several spectral probes by absorption spectroscopy (at wavelengths 410 nm, 530 nm), and circular dichroism (222, 268, 288 and 417 nm). Kinetics monitored with these spectral probes indicates that the oxidative modification of cyt c: i) proceeds in the order: heme → aromatic amino acids → secondary structure, and ii) the rate of the oxidative modification is proportional to the protein flexibility. The flexibility of cyt c was modulated by anions of Hofmeister series (sulfate, chloride, Perchlorate) (Varhač et al. 2009). A minimalist scheme of the interaction of cyt c with hydrogen peroxide can be described by two steps: 1) interaction of hydrogen peroxide with heme iron forming the postulated ferryl intermediate, 2a) oxidation of another molecule of hydrogen peroxide and 2b) parallel oxidation of close amino acid residue(s) and/or heme. The catalase activity of cyt c is independent from the presence of Hofmeister anions, which indicates that both steps (1 and 2a) in the catalase reaction are independent from the flexibility of the heme region of the protein matrix. On the other hand, the flexibility of the polypeptide chain of the protein modulates the rate of parallel oxidative modification of the heme and amino acid residues.

Cite

CITATION STYLE

APA

Tomášková, N., Varinská, L., & Sedlák, E. (2010). Rate of oxidative modification of cytochrome c by hydrogen peroxide is modulated by Hofmeister anions. General Physiology and Biophysics, 29(3), 255–265. https://doi.org/10.4149/gpb_2010_03_255

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free