Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:1.4.3.13 (lysyl oxidase)
1,248 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The biochemistry of the essential trace element copper has been outlined. Following absorption, Cu(II) is transported by serum albumin and transcuprein to the liver where it is incorporated into the plasma Cu-protein, ceruloplasmin, or, possibly, stored as Cu-metallothionein or as superoxide dismutase. Ceruloplasmin is the long-term copper transporter and carries Cu(II) to the tissues for the biosynthesis of key Cu(II) enzymes, especially cytochrome c oxidase, lysyl oxidase and others. The production of copper enzymes raises many new questions about the metabolism of copper. Since ceruloplasmin is the centerpiece of copper metabolism and function, we conclude with more details on its chemistry and multifunctions. This Cu-protein of 132,000 daltons has now been totally sequenced and the copper-containing active sites located. Finally, we have proposed seven possible functions for ceruloplasmin, and there is now good evidence for the existence of ceruloplasmin receptors to expedite some of these functions.
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PMID:Perspectives on copper biochemistry. 300 68

Colorimetry was used to assay blood copper levels in 13 asbestosis patients (mean age 55.5) selected by excluding all cases with an evident clinical anamnesis of dietary imbalances or other significant pathologies. The results show increased blood copper in 11 out of 13 patients, the mean level in this group being significantly higher than that in a control group (p less than 0.01). The phenomenon, already described in other interstitial lung diseases, may well be attributable to enhanced reabsorption of the metal due to the intensified activity of a copper enzyme lysyl oxidase that is involved in collagen synthesis.
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PMID:[Blood copper levels in a group of patients with asbestosis]. 318 50

A previous paper describes specific respiratory toxins likely to be associated with Sudden Infant Death Syndrome (SIDS). This paper describes ultrastructural abnormalities in the lung and other tissues in congenital copper deficiency. Congenital copper deficiency is associated with tissue anoxia defects in the development of myelin through a failure of phospholipid synthesis. Phospholipid is part of the membrane structure of cells. The paucity of elastin is attributed to a loss of lysyl oxidase activity. Hypoventilation is considered a feature of SIDS.
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PMID:Sudden infant death syndrome: congenital copper deficiency. 331 46

There are several known examples of mutations which influence copper homeostasis in humans and animals. Pleiotropic effects are observed when the mutant gene disturbs copper flux. In some cases, the mutation alters the level of a specific copper ligand (enzyme) and the clinical consequences are unique. The two most widely studied genetic maladies in humans are Menkes' and Wilson's diseases. Menkes' disease is an X-linked fatal disorder in which copper accumulates in some organs (intestine and kidney) and is low in others (liver and brain). Wilson's disease is an autosomal recessive disorder in which copper accumulates, if untreated, in liver and subsequently in brain and kidney. Pathophysiological consequences of copper deficiency and toxicity characterize these two disorders. Specific mutations of human cuproenzymes include overproduction of copper-zinc superoxide dismutase in Down's syndrome, absence of tyrosinase in albinism, hereditary mitochondrial myopathy due to reduction in cytochrome c oxidase, and altered lysyl oxidase in X-linked forms of cutis laxa and Ehlers-Danlos syndrome. Mutations altering copper metabolism are also known in animals. Several murine mutants have been studied. The most extensively investigated mutants are the mottled mice, in particular brindled mice, which have a mutation analogous to that of Menkes' disease. Another recently described murine mutation is toxic milk (tx) an autosomal recessive disorder that is characterized by copper accumulation in liver. Two other mutants, crinkled and quaking, were once thought to exhibit abnormal copper metabolism. Recent data has not confirmed this. A mutation in Bedlington terriers has been described which is very similar to Wilson's disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Genetic diseases of copper metabolism. 351 56

Copper is required in trace amounts for many body functions. The prominent effects of Cu deficiency or Cu toxicosis differs greatly between animal species. Along with iron, Cu is necessary for the transfer of O2 via a cascade of enzymes so that energy may be available for vital body functions without overheating of the tissues through rapid oxidation. As a part of lysyl oxidase, Cu has an obligate function in the maturation of all connective tissue (including elastic tissue and bone) maintaining the form and integrity of all body organs. As a constituent of tyrosinase, Cu is involved in the formation of melanin, thus preventing albinism. Copper also is involved in the myelination of nerve fibers and the production of neutrophils, enkephalins, lipoproteins, and cholesterol. Copper must be properly sequestered to prevent toxicosis. Copper is stored primarily as metallothioneins and as superoxide dismutase and is transported primarily as ceruloplasmin or as low molecular weight proteins, peptides, and amino acids.
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PMID:Comparative metabolism of copper. 355 17

We have studied the effects of beta-aminopropionitrile (BAPN) administration on the formation of spontaneous arterial lesions, characterized principally by a rupture in the internal elastic lamina (IEL) in the caudal and renal arteries of the Wistar rat. Treatment with BAPN (an inhibitor of lysyl oxidase) increased the formation of these lesions in rats up to 12 weeks of age but had differential effects on the caudal and renal artery in older rats. Administration of the nitrile to weanling rats led to the premature formation of lesions in caudal arteries of both male and female rats which morphologically resemble lesions which form spontaneously later in life. Dietary supplements of copper or pyridoxine were without effect on the formation of spontaneous caudal artery lesions when given from 5 wks of age but a copper supplement from midgestation slightly inhibited lesion formation only in male rats. This suggests that if copper deficiency is involved in spontaneous lesion formation, it is only a contributory factor. Quantification of either caudal or renal artery lesions within different litters of Wistar rats showed that there exists a familial aggregation in the frequency of spontaneous lesion formation, certain litters showing significantly higher levels of lesions than others. Adult Sprague-Dawley rats also appear to be more susceptible to the development of renal artery IEL defects than Wistar rats. The possibility of a hereditary disorder leading to a minor defect in elastic fibre structure which could be responsible for the spontaneous lesions is discussed.
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PMID:Spontaneous arterial lesions involving breaks in the internal elastic lamina in the rat: effects of beta-aminopropionitrile and familial distribution. 377 Jan 43

In aspartylglycosaminuria (AGU), a lysosomal storage disorder of glycoprotein degradation, there are some abnormalities in collagen and proteoglycan metabolism. Because of earlier observations suggesting a disturbance of copper balance, the metabolism of copper and zinc was studied in more detail to find out if possible trace metal disturbances could be correlated with connective tissue disorder. Highly elevated copper concentrations in the hair and significantly reduced zinc levels in serum and urine were detected in AGU patients indicating a disturbance of trace element balance. However, the patients had normal serum copper levels, and the concentrations of zinc and copper in cultured fibroblasts did not differ from those of control cells. Normal lysyl oxidase activities in cell culture indicate that collagen cross-link formation is not affected. The changes in copper and zinc balance are probably secondary to the basic enzyme deficiency, and may contribute to the development of the clinical signs and symptoms of AGU although the mechanisms involved are not yet understood.
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PMID:Disturbed metabolism of copper and zinc in aspartylglycosaminuria: possible involvement with connective tissue changes. 393 46

Collagen analysis of articular cartilage and subchondral bone was performed on femoral heads obtained from patients of late stage of aseptic necrosis (ANF) (4 cases), and osteoarthritis (OA) (7 cases). In articular cartilage of both diseases, there was not observed any difference in the solubility of collagen compared with normal articular cartilage. However, collagen contents determined by hydroxyproline analysis showed a decrease in both diseases; this tendency was prominent in OA. On the other hand, copper contents showed an increase in ANF while there was a decrease in OA; the fact may suggest that lysyl oxidase acts actively on the formation of a precursor of cross-links in collagen matrix of articular cartilage in ANF. In subchondral bone of both diseases, collagen contents showed an increase in OA, and a decrease in ANF compared with normal subchondral bone. However the solubility of collagen has increased in both diseases. Moreover, lysine hydroxylation and copper contents showed an increase in both OA and ANF; these findings suggest that repairing reaction of the pathological lesion by proliferation of undifferentiated tissue remained even in late stage of the disease. In this paper, the author also discussed about the connective tissue metabolism of these two diseases by determination the types of collagen molecules of pathological cartilage and bone.
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PMID:[Experimental study on the development of aseptic necrosis of femoral head--with comparison of osteoarthritis of the hip in collagen metabolism]. 405 23

Lysyl oxidase activity was found in the isthmus (the membrane-forming region) of the hen's oviduct in a copper-rich region proximal to the shell gland. Desmosine and isodesmosine, cross-linking compounds associated with mature elastin, were found in hydrolysates of the shell membrane, confirming the necessity for lysyl oxidase in its biosynthesis. Shell membranes from hens fed a copper-deficient diet or a diet supplemented with beta-aminopropionitrile had a reduced content of desmosine and isodesmosine.
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PMID:Localization of lysyl oxidase in hen oviduct: implications in egg shell membrane formation and composition. 610 12

We studied several members of a family with an X-linked form of cutis laxa; the affected males have mild skin laxity, a characteristic facies, skeletal abnormalities, structural abnormalities of the genitourinary tract, and low serum copper levels. The activity of lysyl oxidase, a copper-dependent enzyme involved in cross-link formation in collagen, was decreased in skin-biopsy specimens (13 to 26 per cent of normal) and in culture medium from cells to two affected males (15 to 20 per cent of normal). Immunoreactive lysyl oxidase from skin of both patients was virtually undetectable by immunodiffusion assay. The amounts of lysyl-derived aldehydes (the product formed in collagen and elastin by lysyl oxidase) and of cross-links formed from these products were decreased in dermal fibroblasts in culture. Collagen extractability from these cells was increased in culture. These findings suggest that lysyl oxidase deficiency provides the biochemical basis of the X-linked form of cutis laxa.
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PMID:X-linked cutis laxa: defective cross-link formation in collagen due to decreased lysyl oxidase activity. 610 92


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