Premium
Probing Bis‐Fe IV MauG: Experimental Evidence for the Long‐Range Charge‐Resonance Model
Author(s) -
Geng Jiafeng,
Davis Ian,
Liu Aimin
Publication year - 2015
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201410247
Subject(s) - resonance (particle physics) , chemistry , range (aeronautics) , charge (physics) , molecule , atomic physics , materials science , physics , organic chemistry , quantum mechanics , composite material
The biosynthesis of tryptophan tryptophylquinone, a protein‐derived cofactor, involves a long‐range reaction mediated by a bis‐Fe IV intermediate of a diheme enzyme, MauG. Recently, a unique charge‐resonance (CR) phenomenon was discovered in this intermediate, and a biological, long‐distance CR model was proposed. This model suggests that the chemical nature of the bis‐Fe IV species is not as simple as it appears; rather, it is composed of a collection of resonance structures in a dynamic equilibrium. Here, we experimentally evaluated the proposed CR model by introducing small molecules to, and measuring the temperature dependence of, bis‐Fe IV MauG. Spectroscopic evidence was presented to demonstrate that the selected compounds increase the decay rate of the bis‐Fe IV species by disrupting the equilibrium of the resonance structures that constitutes the proposed CR model. The results support this new CR model and bring a fresh concept to the classical CR theory.