peroxisome

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Peroxisome

An intracellular organelle found in all eukaryotes except the archezoa (original lifeforms). In electron micrographs, peroxisomes appear round with a diameter of 0.1–1.0 micrometer, although there is evidence that in some mammalian tissues peroxisomes form an extensive reticulum (network). They contain more than 50 characterized enzymes and perform many biochemical functions, including detoxification. See Cell organization, Enzyme

Peroxisomes are important for lipid metabolism. In humans, the β-oxidation of fatty acids greater than 18 carbons in length occurs in peroxisomes. In yeast, all fatty acid β-oxidation occurs in peroxisomes. Peroxisomes contain the first two enzymes required for the synthesis of plasmalogens. Peroxisomes also play important roles in cholesterol and bile acid synthesis, purine and polyamine catabolism, and prostaglandin metabolism. In plants, peroxisomes are required for photorespiration. See Lipid metabolism, Photorespiration

A number of recessively inherited peroxisomal disorders have been described and grouped into three categories. Group I is the most severe and is characterized by a general loss of peroxisomal function. Many of the enzymes normally localized to the peroxisome are instead found in the cytosol. Among the diseases found in group I are Zellweger syndrome, neonatal adrenoleukodystrophy, and infantile Refsum disease. Patients with these disorders usually die within the first years after birth and exhibit neurological and hepatic (liver) dysfunction, along with craniofacial dysmorphism (malformation of the cranium and the face). Groups II and III peroxisomal disorders are characterized by a loss of peroxisomal function less severe than in group I.

peroxisome

[pə′räk·sə‚sōm]
(cell and molecular biology)
Any of a subclass of microbodies that contain at least four enzymes involved in the metabolism of hydrogen peroxide.
References in periodicals archive ?
Internationally, the newborn screening laboratory in Taiwan is setting up ALD newborn screening with the help in methodology from the Peroxisomal Laboratory at Kennedy Krieger Institute and positive control samples from the newborn screening group at the Centers for Disease Control.
Peroxisomal membrane protein pmp2 binds to the 53-61 AA region of Siva-1 (4).
The human peroxisomal multifunctional protein involved in bile acid synthesis: activity measurement, deficiency in Zellweger syndrome and chromosome mapping.
The gene closest to the association signal, PECR (which encodes the enzyme peroxisomal trans-2-enoylCoA reductase) is involved in the metabolism of fatty acids, particularly during deprivation when energy expenditure transitions from carbohydrates to fatty acids.
AMN is a disorder due to a deficiency of peroxisomal VLCFA Co-A synthesis and results in accumulation of VLCFAs in the brain and adrenal glands leading to their dysfunction.
450] enzymes, flavoprotein oxidases, and peroxisomal fatty acid metabolism are the most significant intracellular sources of ROS [7].
Supernatant was decanted off in another tube for peroxisomal [beta]-oxidation assay.
Each is a result of peroxisomal dysfunction which affects the brain and the adrenal glands.
Peroxisomal localization of inducible nitric oxide synthase in hepatocytes.
Protein expression profiling of Coccidioides posadasii by two-dimensional differential in-gel electrophoresis and evaluation of a newly recognized peroxisomal matrix protein as a recombinant vaccine candidate.
Brain uptake and utilization of fatty acids: Applications to peroxisomal biogenesis diseases.
Ross Phillipson has a vital enzyme missing in his blood - a peroxisomal disorder which has left him with a number of complications including blindness and impairment to his hearing.