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Copper enzymes azurin

Figure 2.10 Secondary and tertiary structure of the copper enzyme azurin visualized using Wavefunction, Inc. Spartan 02 for Windows from PDB data deposited as 1JOI. See text for visualization details. Printed with permission of Wavefunction, Inc., Irvine, CA. (See color plate.)... Figure 2.10 Secondary and tertiary structure of the copper enzyme azurin visualized using Wavefunction, Inc. Spartan 02 for Windows from PDB data deposited as 1JOI. See text for visualization details. Printed with permission of Wavefunction, Inc., Irvine, CA. (See color plate.)...
Table 5.2 contains data about selected copper enzymes from the references noted. It should be understood that enzymes from different sources—that is, azurin from Alcaligenes denitrificans versus Pseudomonas aeruginosa, fungal versus tree laccase, or arthropodan versus molluscan hemocyanin—will differ from each other to various degrees. Azurins have similar tertiary structures—in contrast to arthropodan and molluscan hemocyanins, whose tertiary and quaternary structures show large deviations. Most copper enzymes contain one type of copper center, but laccase, ascorbate oxidase, and ceruloplasmin contain Type I, Type II, and Type III centers. For a more complete and specific listing of copper enzyme properties, see, for instance, the review article by Solomon et al.4... [Pg.193]

This discussion of copper-containing enzymes has focused on structure and function information for Type I blue copper proteins azurin and plastocyanin, Type III hemocyanin, and Type II superoxide dismutase s structure and mechanism of activity. Information on spectral properties for some metalloproteins and their model compounds has been included in Tables 5.2, 5.3, and 5.7. One model system for Type I copper proteins39 and one for Type II centers40 have been discussed. Many others can be found in the literature. A more complete discussion, including mechanistic detail, about hemocyanin and tyrosinase model systems has been included. Models for the blue copper oxidases laccase and ascorbate oxidases have not been discussed. Students are referred to the references listed in the reference section for discussion of some other model systems. Many more are to be found in literature searches.50... [Pg.228]

There are a number of excellent sources of information on copper proteins notable among them is the three-volume series Copper Proteins and Copper Enzymes (Lontie, 1984). A review of the state of structural knowledge in 1985 (Adman, 1985) included only the small blue copper proteins. A brief review of extended X-ray absorption fine structure (EXAFS) work on some of these proteins appeared in 1987 (Hasnain and Garner, 1987). A number of new structures have been solved by X-ray diffraction, and the structures of azurin and plastocyanin have been extended to higher resolution. The new structures include two additional type I proteins (pseudoazurin and cucumber basic blue protein), the type III copper protein hemocyanin, and the multi-copper blue oxidase ascorbate oxidase. Results are now available on a copper-containing nitrite reductase and galactose oxidase. [Pg.147]

Most copper enzymes and proteins are found only in eukaryotes, but a few copper proteins, such as azurin and plastocyanin are also present in certain prokaryots... [Pg.27]

Enzymes with type (I)/type (2) copper centers Azurin... [Pg.496]

Figure 3 A typical metallo-enzyme, azurin. The copper ion in it is a constrained (entatic) state matching its function. The copper in the enzyme is not open to any substrate—it is an electron-transfer protein. See Reference 8. Figure 3 A typical metallo-enzyme, azurin. The copper ion in it is a constrained (entatic) state matching its function. The copper in the enzyme is not open to any substrate—it is an electron-transfer protein. See Reference 8.
We have investigated in-situ STM of the small single-metal redox proteins cytochrome c (MW 12 kDa) and azurin ( 14 kDa), and the larger four copper-enzyme laccase (MW 64 kDa), all involved in natural ET [51, 54, 55]. The choice rested on the following considerations ... [Pg.38]

Figure 8 Model and proposed reaction cycle for arsenite oxidase from A.faecalis. Reaction steps are (1) binding of arsenite, AsOjOH, to the enzyme, (2) two-electron transfer to Mo, oxidizing As(III) to As(V) and reducing Mo(Vl) to Mo(lV), (3) release of arsenate oxyanion, (4) two-electron transfer from Mo(Vl) to [3Fe-4S] center, regenerating Mo(IV) reaction center, (5) two-electron transfer from [3Fe-4S] center in large subunit to [2Fe-2S] Rieske center of small subunit, and (6) electron transfer from the [2Fe-2S] center of arsenite oxidase to the associated small copper protein azurin. (Based on Refs. 63 and 64.)... Figure 8 Model and proposed reaction cycle for arsenite oxidase from A.faecalis. Reaction steps are (1) binding of arsenite, AsOjOH, to the enzyme, (2) two-electron transfer to Mo, oxidizing As(III) to As(V) and reducing Mo(Vl) to Mo(lV), (3) release of arsenate oxyanion, (4) two-electron transfer from Mo(Vl) to [3Fe-4S] center, regenerating Mo(IV) reaction center, (5) two-electron transfer from [3Fe-4S] center in large subunit to [2Fe-2S] Rieske center of small subunit, and (6) electron transfer from the [2Fe-2S] center of arsenite oxidase to the associated small copper protein azurin. (Based on Refs. 63 and 64.)...
Fig. 4.14 Metal binding sites in copper-containing enzymes (left to right) azurin [32], stellacyanin [33] and haemocyanin [34]... Fig. 4.14 Metal binding sites in copper-containing enzymes (left to right) azurin [32], stellacyanin [33] and haemocyanin [34]...
The type I copper sites function as electron transfer centers in the blue copper proteins and in multicopper enzymes, particularly oxidases (33). They are characterized by their intense blue color, their unusually small A values, and their very positive redox potentials (Table II). X-ray crystal structures of several blue copper proteins have been determined, notably plastocyanin (34), azurin (35), cucumber basic blue protein (36), and pseudoazurin (37). The active site structures show marked similarities but also distinct differences (Fig. 8). [Pg.334]


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See also in sourсe #XX -- [ Pg.31 , Pg.37 , Pg.92 , Pg.192 , Pg.193 , Pg.196 , Pg.215 ]




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