Sandbox Reserved 1104: Difference between revisions

From Proteopedia
Jump to navigationJump to search
No edit summary
No edit summary
Line 10: Line 10:
Multicopper oxidases are enzymes which oxidise their substrate by accepting electrons at a mononuclear copper centre and transferring them to a trinuclear copper centre.<ref>Wikipedia, Multicopper oxidase [https://en.wikipedia.org/wiki/Multicopper_oxidase]</ref>
Multicopper oxidases are enzymes which oxidise their substrate by accepting electrons at a mononuclear copper centre and transferring them to a trinuclear copper centre.<ref>Wikipedia, Multicopper oxidase [https://en.wikipedia.org/wiki/Multicopper_oxidase]</ref>


Bilirubin oxidases are multicopper oxidases containing type 1, type 2, and type 3 coppers. Indeed, there is strong sequence homology between bilirubin oxidase and multicopper oxidases like laccase, ascorbate oxidase and even ceruloplasmin. Moreover, the His-Cys-His sequence, characteristic of multicopper oxidase, is present in bilirubin oxidase. Copper is essential for the enzyme activity.<ref>DOI 10.1021/bi9819531</ref>
Bilirubin oxidases are multicopper oxidases containing type 1, type 2, and type 3 coppers. Indeed, there is strong sequence homology between bilirubin oxidase and multicopper oxidases like laccase, ascorbate oxidase and even ceruloplasmin. Moreover, the His-Cys-His sequence, characteristic of multicopper oxidase, is present in bilirubin oxidase. Copper is essential for the enzyme activity.<ref name="multic">DOI 10.1021/bi9819531</ref>
 
Copper is classified into three types according to their optical and magnetic properties. Type 1 copper (or blue copper) shows many charge-transfer bands around 450 nm, 600 nm and 750 nm. The most peculiar band appears around 600 nm and represents the Cys to Cu(II) charge transfer. Type 2 copper (or nonblue copper) does not show any strong charge-transfer bands in the visible region. Type 3 coppers are not detectable by ESR because some are antiferromagnetically coupled. However, a hydroxide ion links them and so gives a strong absorption at 330 nm.<ref name="multic"/>
While type 2 and 3 coppers reduce dioxygen to two water molecules by forming a trinuclear center, type 1 copper transfers electrons from substrate to the trinuclear center. This is the peculiar sequence His456-Cys457-His458 that forms an intramolecular electron-transfer pathway between the type 1 copper site and the trinuclear center composed of the type 2 and type 3 copper sites.<ref name="multic"/>
 


== Function ==
== Function ==

Revision as of 13:48, 12 January 2020

This Sandbox is Reserved from 25/11/2019, through 30/9/2020 for use in the course "Structural Biology" taught by Bruno Kieffer at the University of Strasbourg, ESBS. This reservation includes Sandbox Reserved 1091 through Sandbox Reserved 1115.
To get started:
  • Click the edit this page tab at the top. Save the page after each step, then edit it again.
  • show the Scene authoring tools, create a molecular scene, and save it. Copy the green link into the page.
  • Add a description of your scene. Use the buttons above the wikitext box for bold, italics, links, headlines, etc.

More help: Help:Editing

Your Heading Here (maybe something like 'Structure')

Caption for this structure

Drag the structure with the mouse to rotate

References