Electrochemistry of copper efflux oxidase-like multicopper oxidases involved in copper homeostasis

Nanomaterials as Redox Mediators in Laccase-Based Amperometric Biosensors for Catechol Assay

“…The traditional understanding of the mechanisms of laccase catalytic activity was that laccase does not require H 2 O 2 as a co-substrate or an additional cofactor for an enzymatic reaction, nor does laccase produce this compound [ 51 ]. However, that postulate was disproven in past decades, when an alternative mechanism of O 2 reduction mediated with laccase was discovered [ 1 , 2 , 7 , 8 , 52 , 53 , 54 , 55 , 56 , 57 , 58 ].…”

“…A number of recombinant and mutant strains have been proposed [ 1 , 2 , 3 , 4 , 5 , 9 , 14 ] to improve the properties of this enzyme which plays important roles in many fields of science, biotechnology, industry, and medicine. Various properties of LMCO were studied, including substrate specificity, structure, and different mechanisms of catalytic activity [ 1 , 2 , 3 , 7 , 52 , 53 , 54 , 55 , 56 , 57 , 58 ].…”

“…The electron transfer (ET) process in laccases, and the mechanism of O 2 reduction as elucidated through spectroscopic, kinetic, crystallographic, and computational data, have been described in several papers [ 1 , 2 , 3 , 52 , 53 , 54 , 55 , 56 ]. Laccases classed as LMCOs contain a minimum of four copper sites, designated as T1, T2, and binuclear T3.…”

“…The main approaches to investigating the ET mechanism are spectroscopic characterization of reaction intermediates, kinetic analysis, oxidation of substrates designed to serve as mechanistic probes, the effect of the addition of radical traps, X-ray devices, and computational analysis [ 2 , 3 , 7 , 53 , 54 , 55 , 56 , 57 , 58 ]. As the result of these high-throughput physical methods, formation of two sequential intermediates, namely “peroxide (PI)” and the “native (NI)”, were hypothesized.…”

“…Our results obtained by simple electrochemical methods make a small contribution to the elucidation of the mechanism of catalytic activity of laccase. A deeper knowledge of the pathways of Cu-promoted laccase activity—namely details of the changes in ET and/or proton transfer rates—will provide better understanding of how nature controls the process of O 2 reduction to H 2 O [ 1 , 2 , 3 , 7 , 56 , 57 , 58 , 59 ]. Additionally, this knowledge will also be of practical importance for biomedical applications and industrial processes.…”