Monooxygenase: Difference between revisions
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'''Monooxygenases''' (MO) catalyzes the incorporation of a hydroxyl group into a variety of substrates. MO catalyzes the reduction of O2 to H2O while oxidating NADPH. | '''Monooxygenases''' (MO) catalyzes the incorporation of a hydroxyl group into a variety of substrates. MO catalyzes the reduction of O2 to H2O while oxidating NADPH. | ||
=== Peptidylglycine α-Hydroxylating Monooxygenase (PHM)-coordination of peroxide to Cu<sub>M</sub> center. Structural and computational study | === Peptidylglycine α-Hydroxylating Monooxygenase (PHM)-coordination of peroxide to Cu<sub>M</sub> center. Structural and computational study <ref >doi 10.1007/s00775-012-0967-z</ref>=== | ||
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 <scene name='Journal:JBIC:17/Cv/8'>interatomic O-O distance of the copper-bound ligand is 1.5, characteristic of peroxide/hydroperoxide species, and the copper-oxygen distances are 2.0 and 2.1</scene> Å. This Cu(II)-bound <scene name='Journal:JBIC:17/Cv/9'>peroxo moiety interacts closely with a molecule of water</scene>, forming <scene name='Journal:JBIC:17/Cv/10'>hydrogen bonds that stabilize the structure</scene>. 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, characteristic of peroxide/hydroperoxide species, and the copper-oxygen distances are 2.0 and 2.1</scene> Å. This Cu(II)-bound <scene name='Journal:JBIC:17/Cv/9'>peroxo moiety interacts closely with a molecule of water</scene>, forming <scene name='Journal:JBIC:17/Cv/10'>hydrogen bonds that stabilize the structure</scene>. 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. | ||