Journal:JBIC:17
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<b>Molecular Tour</b><br> | <b>Molecular Tour</b><br> | ||
In recent years there has been a significant interest in describing the interactions of copper-containing enzymes with O2/H2O2-derived species. The short-lived intermediates resulting from the activation of dioxygen are the key players in the mechanistic cycles in many metalloenzymes. In the enzyme <scene name='Journal:JBIC:17/Cv/3'>peptidylglycine alpha-hydroxylating monooxygenase (PHM)</scene> various reduced Cu/oxygen species have been proposed to act as catalytically competent intermediates, yet their exact nature and their role in the enzymatic reaction is still unknown. | In recent years there has been a significant interest in describing the interactions of copper-containing enzymes with O2/H2O2-derived species. The short-lived intermediates resulting from the activation of dioxygen are the key players in the mechanistic cycles in many metalloenzymes. In the enzyme <scene name='Journal:JBIC:17/Cv/3'>peptidylglycine alpha-hydroxylating monooxygenase (PHM)</scene> various reduced Cu/oxygen species have been proposed to act as catalytically competent intermediates, yet their exact nature and their role in the enzymatic reaction is still unknown. | ||
| - | Structural and other studies showed that peptidylglycine α-hydroxylating monooxygenase (PHM) contains <scene name='Journal:JBIC:17/Cv/4'>two non-equivalent copper sites (CuH and CuM)</scene>. CuM serves as an oxygen binding and hydrogen abstraction site, CuH is involved in electron transfer. In the structure of Cu(II)-PHM complexed with hydrogen peroxide determined to 1.98 Å resolution, <scene name='Journal:JBIC:17/Cv/7'>(hydro)peroxide binds exclusively to CuM in a slightly asymmetric side-on mode</scene>. The interatomic O-O distance of the copper-bound ligand is 1.5 Å, characteristic of peroxide/hydroperoxide species, and the copper-oxygen distances are 2.0 and 2.1. This Cu(II)-bound peroxo moiety interacts closely with a molecule of water, forming hydrogen bonds that stabilize the structure. DFT and QM/MM calculations indicate that this species is a Cu-bound doubly deprotonated peroxidate and that its energy is similar to that of its isomer Cu(I)-bound superoxide. | + | Structural and other studies showed that peptidylglycine α-hydroxylating monooxygenase (PHM) contains <scene name='Journal:JBIC:17/Cv/4'>two non-equivalent copper sites (CuH and CuM)</scene>. CuM serves as an oxygen binding and hydrogen abstraction site, CuH is involved in electron transfer. In the structure of Cu(II)-PHM complexed with hydrogen peroxide determined to 1.98 Å resolution, <scene name='Journal:JBIC:17/Cv/7'>(hydro)peroxide binds exclusively to CuM in a slightly asymmetric side-on mode</scene>. The <scene name='Journal:JBIC:17/Cv/8'>interatomic O-O distance of the copper-bound ligand is 1.5 Å, characteristic of peroxide/hydroperoxide species, and the copper-oxygen distances are 2.0 and 2.1</scene>. This Cu(II)-bound peroxo moiety interacts closely with a molecule of water, forming hydrogen bonds that stabilize the structure. DFT and QM/MM calculations indicate that this species is a Cu-bound doubly deprotonated peroxidate and that its energy is similar to that of its isomer Cu(I)-bound superoxide. |
Revision as of 12:16, 17 December 2012
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This page complements a publication in scientific journals and is one of the Proteopedia's Interactive 3D Complement pages. For aditional details please see I3DC.
