Related Experiment Video
Updated: Mar 29, 2026

EPR Monitored Redox Titration of the Cofactors of Saccharomyces cerevisiae Nar1
Published on: November 26, 2014
Design of a single protein that spans the entire 2-V range of physiological redox potentials
Parisa Hosseinzadeh1, Nicholas M Marshall2, Kelly N Chacón3
1Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL 61801;
Abstract:
The reduction potential (E°') is a critical parameter in determining the efficiency of most biological and chemical reactions. Biology employs three classes of metalloproteins to cover the majority of the 2-V range of physiological E°'s. An ultimate test of our understanding of E°' is to find out the minimal number of proteins and their variants that can cover this entire range and the structural features responsible for the extreme E°'. We report herein the design of the protein azurin to cover a range from +970 mV to -954 mV vs. standard hydrogen electrode (SHE) by mutating only five residues and using two metal ions. Spectroscopic methods have revealed geometric parameters important for the high E°'. The knowledge gained and the resulting water-soluble redox agents with predictable E°'s, in the same scaffold with the same surface properties, will find wide applications in chemical, biochemical, biophysical, and biotechnological fields.
Related Concept Videos
Redox Equilibria: Overview
Redox Reactions
Redox Reactions
Ladder Diagrams: Redox Equilibria
Consider the Fe3+/Fe2+ half-reaction, which has a standard-state potential of +0.771 V. At potentials more positive than +0.771 V, Fe3+ predominates, whereas Fe2+...
The Supercomplexes in the Crista Membrane
Balancing Redox Equations

