Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.10.3.3 (ascorbate oxidase)
 778 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Unheated press juice (PJ) obtained from chicken breast muscle was a potent inhibitor of hemoglobin-mediated lipid oxidation in washed cod muscle. The <1 kDa fraction had a negligible effect on the rate of lipid oxidation. The high-molecular-weight (HMW) fraction was mildly inhibitory when added alone and highly inhibitory in the presence of <1 kDa components. Proteins of the HMW fraction were further fractionated by ammonium sulfate precipitation. Proteins in the 80% fraction were most inhibitory compared with other precipitated fractions on an equal protein basis. Inhibition by PJ was substantially decreased due to treatment with ascorbate oxidase. Adding ascorbate to the HMW fraction did not increase its inhibition, which suggested the presence of a complex ascorbate-reducing system in PJ consisting of HMW and low-molecular-weight (LMW) components. The ability of added ceruloplasmin to inhibit lipid oxidation was remarkably enhanced by addition of ascorbate or the <1 kDa fraction. Heated and centrifuged PJ had 8 times more LMW iron compared to unheated PJ. Adding heated PJ to washed cod containing hemoglobin slightly increased the rate and extent of lipid oxidation.
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PMID:Characterization of aqueous components in chicken breast muscle as inhibitors of hemoglobin-mediated lipid oxidation. 1568 32

The electrochemistry of some copper-containing proteins and enzymes, viz. azurin, galactose oxidase, tyrosinase (catechol oxidase), and the "blue" multicopper oxidases (ascorbate oxidase, bilirubin oxidase, ceruloplasmin, laccase) is reviewed and discussed in conjunction with their basic biochemical and structural characteristics. It is shown that long-range electron transfer between these enzymes and electrodes can be established, and the mechanistic schemes of the DET processes are proposed.
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PMID:Direct electron transfer between copper-containing proteins and electrodes. 1585 24

Multicopper oxidases (MCOs) are a specific group of enzymes that contain multiple copper centers through which different substrates are oxidized. Main members of MCO family include ferroxidases, ascorbate oxidases, and laccases. MCO type of ferroxidases is key to iron transport across the plasma membrane. In Drosophila, there are four potential multicopper oxidases, MCO1-4. No convincing evidence has been presented so far to indicate any of these, or even any insect multicopper oxidase, to be a ferroxidase. Here we show Drosophila MCO3 (dMCO3) is highly likely a bona fide ferroxidase. In vitro activity assay with insect-cell-expressed dMCO3 demonstrated it has potent ferroxidase activity. Meanwhile, the ascorbate oxidase and laccase activities of dMCO3 are much less significant. dMCO3 expression in vivo, albeit at low levels, appears mostly extracellular, reminiscent of mammalian ceruloplasmin in the serum. A null dMCO3 mutant, generated by CRISPR/Cas9 technology, showed disrupted iron homeostasis, evidenced by increased iron level and reduced metal importer Mvl expression. Notably, dMCO3-null flies phenotypically are largely normal at normal or iron stressed-conditions. We speculate the likely existence of a similar iron efflux apparatus as the mammalian ferroportin/ferroxidase in Drosophila. However, its importance to fly iron homeostasis is greatly minimized, which is instead dominated by another iron efflux avenue mediated by the ZIP13-ferritin axis along the ER/Golgi secretion pathway.
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PMID:Drosophila multicopper oxidase 3 is a potential ferroxidase involved in iron homeostasis. 2968 24


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