A biosynthetic model of cytochrome c oxidase as an electrocatalyst for oxygen reduction.

Nature communications (2015-10-13)
Sohini Mukherjee, Arnab Mukherjee, Ambika Bhagi-Damodaran, Manjistha Mukherjee, Yi Lu, Abhishek Dey
RESUMEN

Creating an artificial functional mimic of the mitochondrial enzyme cytochrome c oxidase (CcO) has been a long-term goal of the scientific community as such a mimic will not only add to our fundamental understanding of how CcO works but may also pave the way for efficient electrocatalysts for oxygen reduction in hydrogen/oxygen fuel cells. Here we develop an electrocatalyst for reducing oxygen to water under ambient conditions. We use site-directed mutants of myoglobin, where both the distal Cu and the redox-active tyrosine residue present in CcO are modelled. In situ Raman spectroscopy shows that this catalyst features very fast electron transfer rates, facile oxygen binding and O-O bond lysis. An electron transfer shunt from the electrode circumvents the slow dissociation of a ferric hydroxide species, which slows down native CcO (bovine 500 s(-1)), allowing electrocatalytic oxygen reduction rates of 5,000 s(-1) for these biosynthetic models.

MATERIALES
Referencia del producto
Marca
Descripción del producto

Sigma-Aldrich
Sodium phosphate dibasic dihydrate, BioUltra, for molecular biology, ≥99.0% (T)
Sigma-Aldrich
Sodium phosphate dibasic dihydrate, puriss. p.a., reag. Ph. Eur., 98.5-101.0% (calc. to the dried substance)
Sigma-Aldrich
Sodium phosphate dibasic dihydrate, meets analytical specification of Ph. Eur., BP, 98.5-101% (calc. to the dried substance)
Sigma-Aldrich
6-Mercaptohexanoic acid, 90%