Sandbox Reserved 1104: Difference between revisions
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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 name="multic">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"/> | 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"/> | ||
