TY - JOUR
T1 - Shall we dance? How a multicopper oxidase chooses its electron transfer partner
AU - Quintanar, Liliana
AU - Stoj, Christopher
AU - Taylor, Alexander B.
AU - Hart, P. John
AU - Kosman, Daniel J.
AU - Solomon, Edward I.
PY - 2007/6
Y1 - 2007/6
N2 - Multicopper oxidases (MCOs) are encoded in the genomes of Eukarya, Bacteria, and Archea. These proteins are unique in that they contain at least four Cu atom prosthetic groups organized into one each of the three spectral classifications of copper sites in biology: type 1 (T1), type 2 (T2), and binuclear type 3 (T3), where the T2 and T3 sites form a trinuclear Cu cluster. With these four redox-active copper sites, the multicopper oxidases catalyze the four-electron (4e-) reduction of dioxygen to 2H2O, an activity that they alone share with the terminal heme-containing oxidases. Most MCOs exhibit broad specificity towards organic reductants, while a relatively small number of family members exhibit equally robust activity towards metal ions like FeII, CuI, and MnII and, thus, are considered metallo-oxidases. This Account analyzes the structure-activity features of multicopper oxidases that determine their relative substrate specificity. Since the substrate oxidation step involves an outer-sphere electron transfer from the reductant to the T1Cu site in the protein, the concepts of Marcus theory are applied to unravel the origin of the substrate specificity of the multicopper ferroxidases.
AB - Multicopper oxidases (MCOs) are encoded in the genomes of Eukarya, Bacteria, and Archea. These proteins are unique in that they contain at least four Cu atom prosthetic groups organized into one each of the three spectral classifications of copper sites in biology: type 1 (T1), type 2 (T2), and binuclear type 3 (T3), where the T2 and T3 sites form a trinuclear Cu cluster. With these four redox-active copper sites, the multicopper oxidases catalyze the four-electron (4e-) reduction of dioxygen to 2H2O, an activity that they alone share with the terminal heme-containing oxidases. Most MCOs exhibit broad specificity towards organic reductants, while a relatively small number of family members exhibit equally robust activity towards metal ions like FeII, CuI, and MnII and, thus, are considered metallo-oxidases. This Account analyzes the structure-activity features of multicopper oxidases that determine their relative substrate specificity. Since the substrate oxidation step involves an outer-sphere electron transfer from the reductant to the T1Cu site in the protein, the concepts of Marcus theory are applied to unravel the origin of the substrate specificity of the multicopper ferroxidases.
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U2 - 10.1021/ar600051a
DO - 10.1021/ar600051a
M3 - Article
C2 - 17425282
AN - SCOPUS:34447310586
SN - 0001-4842
VL - 40
SP - 445
EP - 452
JO - Accounts of Chemical Research
JF - Accounts of Chemical Research
IS - 6
ER -