Detoxification copper

DNA-binding activity (Furst et al., 1988 Thiele, 1988 Szczypka and Thiele, 1989 Dameron et al., 1991). As outhned helow. Mad and Acel work cooperatively and reciprocally, sensing the amount of copper in the cytoplasmic environment and turning on and off the transcription of genes encoding the copper import and copper detoxification/sequestra-tion proteins as appropriate. 

Eide, D. J., Bridgham, J. T, Zhao, Z., and Mattoon, J. R. (1993). The vacuolar H -ATPase of Saccharomyces cerevisiae is required for efficient copper detoxification, mitochondrial function, and iron metabolism. Mol. Gen. Genet. 241, 447 56. 

FSM Sosnowiec manufactures automobile lamps, door locks, and window winders for the Polish-manufactured Fiat cars. The lamp bodies are made of zinc-aluminum alloy and then copper-nickel-chromium plated. The door locks and window winders are made of steel and then zinc plated. The wastestreams contain cyanide and the heavy metals chromium (VI), copper, zinc, and nickel. The company carries out the traditional treatments of detoxification, neutralization, and dewatering.29... 

Copper is part of several essential enzymes including tyrosinase (melanin production), dopamine beta-hydroxylase (catecholamine production), copper-zinc superoxide dismutase (free radical detoxification), and cytochrome oxidase and ceruloplasmin (iron conversion) (Aaseth and Norseth 1986). All terrestrial animals contain copper as a constituent of cytochrome c oxidase, monophenol oxidase, plasma monoamine oxidase, and copper protein complexes (Schroeder et al. 1966). Excess copper causes a variety of toxic effects, including altered permeability of cellular membranes. The primary target for free cupric ions in the cellular membranes are thiol groups that reduce cupric (Cu+2) to cuprous (Cu+1) upon simultaneous oxidation to disulfides in the membrane. Cuprous ions are reoxidized to Cu+2 in the presence of molecular oxygen molecular oxygen is thereby converted to the toxic superoxide radical O2, which induces lipoperoxidation (Aaseth and Norseth 1986). 

When animals are fed experimental diets lacking copper or zinc, their copper or zinc status rapidly declines, suggesting that there is not a storage pool of these metals. Thus, while the small, cysteine-rich protein metallothionein (see below) can avidly bind zinc and copper, this may reflect its role in detoxification rather than as a specific storage form. This is reflected by the fact that metallothionein genes are typically expressed at a basal level, but their transcription is strongly induced by heavy metal load. 

Chen F, Deng Z, Li X, Zhang J, Zhao J. Visible hght detoxification by 2,9,16,23-tetracar-boxyl phthalocyanine copper modified amorphous titania. Chem Phys Lett 2005 415 85-8. 

In a case-control study in 106 heroin-dependent individuals undergoing an opioid detoxification program (n = 19) or a methadone maintenance treatment program (n = 87) there were large significant differences in the mean values of some vitamins and minerals between the heroin-dependent individuals and the healthy, non-dependent controls (37). Dependent individuals had higher white cell counts and transaminases and lower erythrocyte counts and cholesterol, albumin, tocopherol, folic acid, sodium, selenium, and copper concentrations. 

Fig. 1. Schematic overview of copper trafficking and homeostasis inside the yeast cell. The actions of Mad and Ace 1, copper-dependent metalloregulatory transcription factors, control the production of copper import [copper transporter (Ctr) and reductase (Fre)] and detoxification/sequestration [metallothionein (MT)] machineries, respectively. Three chaperone-mediated delivery pathways are shown. Atxl shuttles Cu(I) to the secretory pathway P-type ATPase Ccc2 (right). CCS delivers Cu(I) to the cytoplasmic enzyme copper-zinc superoxide dismutase (SOD) (left). Coxl7 shuttles Cu(I) to cytochrome c oxidase (CCO) in the mitochondria (bottom). Mitochondrial proteins Scol and Sco2 may also play a role in copper delivery to the CuA and CuB sites of CCO. Copper metabolism and iron metabolism are linked through the actions of Fet3, a copper-containing ferroxidase required to bring iron into the cell (lower right) (see text).

Another common biomarker for trace metal exposure is the metal-binding protein metallothionein, which regulates normal zinc and copper metabolism and provides a mechanism for metal detoxification. Changes in metallothionein activity provide a sensitive marker of trace metal exposure. 

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