Copper coordination domain

One of the earliest Schiff base macrocycles to exhibit a haemocyanine-like structure was the copper(II) perchlorate complex of 5.5 which binds readily to azide or hydroxide.8 The azide complex exhibits two square pyramidal copper binding domains with the basal plane occupied by one pyridyl nitrogen atom and two imine functionalities as well as a terminal azide ligand. The apices of the two pyramidal coordination polyhedra are linked by a single bridging azide anion. Continuing the biomimetic theme, manganese (II) cascade complexes of the unsymmetrical 5.6 have... 

A keyword search will provide access to coordinate sets from all species that are currently available as well as various site-directed mutants, type 1 copper proteins substituted with metals other than copper, and ruthenated blue copper protein derivatives. Table 1 provides a summary (with references) of the structures of blue copper-binding domains elucidated using X-ray crystallography and NMR spectroscopy. 

Figure 27 Ribbon diagram of the monomer of quercetin 2,3-dioxygenase. The N-terminal domain is shown in yellow and the C-terminal domain in brown, and a-helices are displayed in blue. The linker connecting both domains is colored red. The copper is shown as a green sphere and the copper coordinating residues are represented as ball and stick models. Reproduced from F. Fusetti K. H. Schroter R. A. Steiner P. I. van Noort T. Pijning H. J. Rozeboom K. H. Kalk ...

Figure 12.4 Proposed path for the intracellular transfer of Cu(I) by Atxl. Copper destined for incorporation into the vascular multicopper oxidase Fet3 requires both Ctrl and Ccc2. Cytoplasmic Cu(I)-Atxl, but not apo-Atxl, associates with the amino-terminal domain of Ccc2 and Cu(I) is transferred to the latter. (Inset) A proposed mechanism for the exchange of Cu(I) involving two- and three-coordinate Cu-bridged intermediates. The human homologues of Atxl (Hahl), Ccc2 (Menkes and Wilson s proteins) and Fet3 (ceruloplasmin) are likely to employ similar mechanisms. Reprinted with permission from Pufahl et al., 1997. Copyright (1997) American Association for the Advancement of Science.

Several models for the structure of the twin walls have been proposed (30, and ref. therein). The simplest of these is illustrated in Figure 4. The twin wall is formed by three consecutive diagonals. The copper atoms located on the central one have two-fold coordination with corresponding oxygen stoichiometry of x = 6.0. Those located on the two neighboring rows on each side of the central diagonal have three-fold coordination and oxygen stoichiometry x = 6.5. Within each domain, away from the boundary, the composition is x = 7.0 and copper has the usual four-fold planar coordination of... 

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