Work

Modulating Heme Redox Potential Through Protein-Induced Porphyrin Distortion

Year: 2010

Type: article

Abstract: Hemoproteins are ubiquitous in biology and are commonly involved in critical processes such as electron transfer, oxidative phosphorylation, and signal transduction. Both the protein environment and the heme cofactor contribute to generate the range of chemical properties needed for these diverse functions. Using the heme nitric oxide/oxygen binding (H-NOX) protein from the thermophilic bacterium Thermoanaerobacter tengcongensis, we have shown that heme electronic properties can be modulated by porphyrin distortion within the same protein scaffold without changing the heme ligation state or heme environment. The degree of heme distortion was found to be directly correlated to the electron density at the heme iron, as evidenced by dramatic changes in the heme redox potential and pK(a) of the distal ligand ((-)OH vs H(2)O). Protein-induced porphyrin distortion represents a new strategy to rationally tune the electronic properties of protein-bound porphyrins and could be used to engineer proteins with desired reactivity or functionality.

Source: Journal of the American Chemical Society

DOI: 10.1021/ja106252b

Authors: Charles Olea, John Kuriyan, Michael A. Marletta

Institutions: QB3, University of California, Berkeley

Language: English

Topic: Porphyrin and Phthalocyanine Chemistry

Subfield: Materials Chemistry

Field: Materials Science

Domain: Physical Sciences

Open Access status: green

Funder: National Institute of General Medical Sciences

Awards: G1178845421, Heme Protein Sensors in Prokaryotes