JBIC Journal of Biological Inorganic Chemistry

, Volume 15, Issue 1, pp 15–28

Multicopper oxidases: a workshop on copper coordination chemistry, electron transfer, and metallophysiology

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DOI: 10.1007/s00775-009-0590-9

Cite this article as:
Kosman, D.J. J Biol Inorg Chem (2010) 15: 15. doi:10.1007/s00775-009-0590-9

Abstract

Multicopper oxidases (MCOs) are unique among copper proteins in that they contain at least one each of the three types of biologic copper sites, type 1, type 2, and the binuclear type 3. MCOs are descended from the family of small blue copper proteins (cupredoxins) that likely arose as a complement to the heme-iron-based cytochromes involved in electron transport; this event corresponded to the aerobiosis of the biosphere that resulted in the conversion of Fe(II) to Fe(III) as the predominant redox state of this essential metal and the solubilization of copper from Cu2S to Cu(H2O)n2+. MCOs are encoded in genomes in all three kingdoms and play essential roles in the physiology of essentially all aerobes. With four redox-active copper centers, MCOs share with terminal copper-heme oxidases the ability to catalyze the four-electron reduction of O2 to two molecules of water. The electron transfers associated with this reaction are both outer and inner sphere in nature and their mechanisms have been fairly well established. A subset of MCO proteins exhibit specificity for Fe2+, Cu+, and/or Mn2+ as reducing substrates and have been designated as metallooxidases. These enzymes, in particular the ferroxidases found in all fungi and metazoans, play critical roles in the metal metabolism of the expressing organism.

Keywords

Multicopper oxidase Electron transfer Copper coordination Iron metabolism Protein evolution 

Abbreviations

Cp

Ceruloplasmin

hCp

Human ceruloplasmin

Hp

Hephaestin

LUMO

Lowest unoccupied molecular orbital

MCO

Multicopper oxidase

NiR

Nitrite reductase

SLAC

Small laccase

T1

Type 1

T2

Type 2

T3

Type 3

TNC

Trinuclear cluster

Copyright information

© SBIC 2009

Authors and Affiliations

  1. 1.Department of BiochemistryThe University at BuffaloBuffaloUSA