Dinuclear copper proteins

The reaction of binuclear copper complexes with oxygen as models for tyrosinase activity was also markedly accelerated by applying pressure (106408 ). Tyrosinase is a dinuclear copper protein which catalyses the hydroxylation of phenols. This reaction was first successfully modeled by Karlin and co-workers (109), who found that an intramolecular hydroxylation occurred when the binuclear Cu(I) complex of XYL-H was treated with oxygen (Scheme 5). 

ABSTRACT. Models of metallo-enzymes and -proteins e.g. iron-sulfur proteins, dinuclear copper proteins, and monooxygenases are described. In particular, the potential role of these complexes as supramolecular catalysts is explored. 

There are three classes of proteins that reversibly bind dioxygen. Hemoglobins occur in a wide variety of organisms, having active sites with a single iron pro-toprophyrin IX cofactor. Hemerythrins are nonheme diiron proteins present in certain species of seaworms. The hemocyanins are dinuclear copper proteins found in the hemolymph of mollusks and arthropods. There have been extensive studies on the physical and structural properties of these proteins, and only a brief mention of their active site structures will be discussed here [9]. 

In homo-dinuclear systems, such as two copper(ll) ions, no large effects are expected on the electron relaxation rates as the two metal ions relax at the same rate. However, some other relaxation mechanisms are operative, giving rise to faster electron relaxation rates (dementi and Luchinat, 1998). Consequently, nuclear relaxation is slower than in single copper(ll) systems. Several examples from model complexes are available (Brink et al., 1996 Murthy et al., 1997), as well as from a copper(ll)-substituted zinc enzyme, the aminopeptidase from Aeromonas proteolytica (Holz et al., 1998). In contrast, few NMR studies on native copper proteins containing two coupled copper (II) ions have been reported so far (Bubacco cf a/., 1999). 

Copper Proteins Oxidases Copper Proteins with Dinuclear Active Sites Cytochrome Oxidase. 

Copper Enzymes in Denitrification Copper Hemo-cyanin/Tyrosinase Models Copper OrganometalUc Chemistry Copper Proteins Oxidases Copper Proteins with Dinuclear Active Sites Copper Proteins with Type 1 Sites Superconductivity. 

Based in part on the article Copper Proteins with Dinuclear Active Sites by Konrad Lerch which appeared in the Encyclopedia of Inorganic Chemistry, First Edition. 

COPPER PROTEINS WITH DINUCLEAR ACTIVE SITES... 

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