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Metalloproteins containing

Metalloproteins contain metal atoms Ferritin Iron 35... [Pg.127]

A detailed analysis of Ni11 complexes with mew-substituted porphyrins bearing zero, one, two, or four /-butyl groups revealed that both the out-of-plane and in-plane distortion depend on the perturbation symmetry of the peripheral substituents (number and position of substitutents), and their orientation.1775 These results have implications for understanding the role of nonplanar distortions in the function of metalloproteins containing nonplanar porphyrins.1776... [Pg.412]

Nickel is considered essential to animals because it is present in the fetus or newborn, is homeostatically regulated, the metabolic pool of nickel is specifically influenced by hormonal substances or pathologic processes, certain metalloproteins contain nickel, and because nickel deficiency has been induced experimentally in certain species of birds and animals (NAS 1975 USPHS 1977 Kirchgessner and Schnegg 1980). In general, the nickel deficiency syndrome can be cured or prevented by trace amounts of nickel (NAS 1975). However, nickel administration may not be successful in reversing all abnormalities produced by nickel deprivation (USPHS 1977). [Pg.485]

Usually, these metalloproteins contain both type 2 and type 3 copper centers, together forming a triangular-shaped trinuclear active site, such as found in laccase (polyphenol oxidase) [38-41] and ascorbate oxidase (3) [42]. Recent evidence for a related arrangement has been reported for the enzyme particulate methane monooxygenase as well [43], but in this case the Cu Cu distance of the type 2 subunit (2.6 A) appears to be unusually short and the third Cu ion is located far from the dinuclear site. [Pg.29]

Many metalloproteins contain more than one metal center. Tyrosinase, for example, has a dinuclear Type 3 (T3) copper active site which, in its oxidized form, comprises two Cu(II) centers each held by three histidine groups with a p-r 2 r 2 peroxido bridging ligand (Fig. 22). [Pg.24]

Many of the biologically active zinc metalloproteins contain a zinc(II) ion bound to one or more imidazole ligands of the amino add residue histidine. For this reason a large number of studies over an extended period have been carried out on zinc and cadmium complexes of imidazole, substituted imidazoles, histidine and related ligands. There has also been much recent activity in this field much structural information is available. [Pg.948]

However, the changes in environment which occurred with the change from a reductive to an oxidative atmosphere rendered iron sulfide-based redox systems inconvenient, as they were very sensitive to (irreversible) oxidation. We saw in earlier chapters the facile formation of porphyrin and phthalocyanines from relatively simple precursors, and these systems were adopted for the final steps of electron transfer in oxidative conditions. The occurrence of iron centres in planar tetradentate macrocycles is ubiquitous, and metalloproteins containing such features are involved in almost every aspect of electron transfer and dioxygen metabolism. A typical example is seen in the electron transfer protein cytochrome c (Fig. 10-10). [Pg.297]

Another type of cysteine-containing metalloprotein which has M-S(cys) bonding at the active site is present in electron transfer proteins or metalloenzymes. Sulfur coordination is an important feature, and the covalency and soft environment are possible prerequisites for efficient electron transfer leading to redox catalysis. A distortion at the metal site is induced by the peptide ligands and is a significant feature of the active sites in metalloproteins containing transition metals Fe, Cu, Ni, Mo, etc. [Pg.41]

Subsequently, Nitta et al. (1987) concluded that equine lysozyme was a metalloprotein, containing one Ca(II) ion per molecule. They recently determined for binding of Ca(II) by equine and pigeon lysozymes to be 2 X 10 M" and 1.6 x 10 M", respectively (Nitta et al., 1988). More recently Desmet et al. (1989) found that removal of Ca(II) from equine lysozyme induces a small but significant change in CD behavior, indicating a slightly unfolded apo conformation, apparently similar to that of the apo form of a-lactalbumin. [Pg.222]

Laccase was discovered in 1883 by Yoshida (4), who found that the latex of the Chinese or Japanese lacquer tree rapidly hardened to a plastic in the presence of oxygen, and he attributed this to the presence of a diastase in the lacquer. A few years later Bertrand (5) further purified this enzyme and named it laccase. He suggested that laccase is a metalloprotein containing manganese and introduced the term oxidase. About 50 years later Keilin and Mann (6) demonstrated that laccase is a copper enzyme and showed that its blue color disappears reversibly upon addition of substrate. Laccase has been extensively reviewed by the researchers in this field over the last 20 years, and a representative selection is listed (3, 7-12). [Pg.122]

Design and engineering of metalloproteins containing non-native cofactors through noncovalent attachment... [Pg.1306]

Lu Y. Design and engineering of metalloproteins containing unnatural amino acids or non-native metal-containing cofactors. Curr. Opin. Chem. Biol. 2005 9 118-126. [Pg.1309]

Although we have focused on individual structural units in rubredoxins, ferredoxins and HIPIPs, we should note that some metalloproteins contain more than one Fe S unit. For example, the ferredoxin isolated from Azotobacter vinelandii contains both [4Fe S] and [3Fe-4S] units, with the closest Fe-"-Fe separation between units being i930 pm. [Pg.848]

Enzyme Concentration and Purification. The number of existing enzymes is estimated to be more than 10,000 of which more than 100 have been purified in crystalline form and over 600 in fairly purified form. The molecular weight of enzymes varies from 12,700 (ribonuclease) to over 1,000,000 (L-glutamate dehydrogenase, d-carboxylase). All enzymes are proteins, conjugated proteins or metalloproteins containing one or more active sites per molecule. [Pg.242]


See other pages where Metalloproteins containing is mentioned: [Pg.128]    [Pg.254]    [Pg.293]    [Pg.298]    [Pg.305]    [Pg.111]    [Pg.145]    [Pg.71]    [Pg.88]    [Pg.280]    [Pg.59]    [Pg.229]    [Pg.40]    [Pg.65]    [Pg.1163]    [Pg.5543]    [Pg.190]    [Pg.114]    [Pg.122]    [Pg.754]    [Pg.17]    [Pg.18]    [Pg.18]    [Pg.1720]    [Pg.800]    [Pg.124]    [Pg.167]    [Pg.130]    [Pg.226]    [Pg.317]    [Pg.88]    [Pg.859]    [Pg.1162]    [Pg.5186]    [Pg.5542]   


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Metalloprotein

Metalloproteins

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