Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.16.3.1 (ceruloplasmin)
 5,074 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Liver endothelium can remove and transport the glycoprotein transferrin (TF). During this process the molecules are desialylated; however, in contrast with other such glycoproteins, for example caeruloplasmin, only half of transported TF is desialylated. To explore which component of TF is desialylated, we double-labelled fully sialylated TF with [3H]sialic acid residues and a 125I-protein moiety. This was then 'chased' through purified liver endothelium in pulse-chase experiments. Endothelium-conditioned TF was fractionated on an RCA120 affinity column into sialylated and desialylated components. Each component was then re-fractionated on a concanavalin A affinity column, which separates the glycoprotein according to the branching pattern of its glycan chain. The desialylated fraction was eluted only as a triantennary component, whereas the non-desialylated fraction consisted only of bi- and tetra-antennary chains. The significance of this selective desialylation of triantennary chain of TF in the subsequent metabolism of its iron content and its possible role in the pathogenesis of alcohol-induced hepatic siderosis are discussed.
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PMID:Desialylation of transferrin by liver endothelium is selective for its triantennary chain. 259 20

Diverse clinical disorders distinct from hereditary hemochromatosis are associated with accumulation of excess body iron in heterogeneous patterns and through various mechanisms. A deranged iron turnover somehow relates to the altered physiological barrier for iron absorption in several defined chronic anemias with ineffective erythropoiesis. Unexcretable excess iron acquired from transfusions provides a therapeutic challenge. Genetic defects of proteins essential for transport of iron into and out of cells (transferrin and ceruloplasmin) deprive the erythron of the metal and cause its accumulation in other vital organs. The hemochromatosis alleles predictably contribute to an iron burden from other causes, commonly facilitate the expression of porphyria cutanea tarda, and their clinical expression may be accelerated by hereditary hemolytic anemias. Even minimal iron excess in liver disease may contribute to the hepatocellular injury from factors such as alcohol and viruses. Uniquely localized siderosis occurs in the lung and kidney where iron cannot turn over and causes variable tissue damage. The most devastating iron overload disorder, neonatal hemochromatosis, is understood least of all.
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PMID:Secondary iron overload disorders. 946 Aug 11

A 63-year-old woman with a past history of right subdural hematoma (SDH) at the age of 61 years was referred to our hospital under a suspicion of aceruloplasminemia (ACP). A neurological examination revealed very mild cognitive impairment and cerebellar ataxia. Blood chemistry data showed deficient ceruloplasmin (Cp), decreased copper, and increased ferritin. A nonsense mutation (c.2630G>A, p.Trp858Ter) was detected in the Cp gene. Brain magnetic resonance imaging (MRI) showed marked hypointensity at the surface of the cerebrum, cerebellum, and brainstem bilaterally, in addition to the bilateral basal ganglia, thalamus, and dentate nucleus, suggesting the coexistence of ACP and superficial siderosis (SS). The characteristics of SS in ACP have not been examined neuroradiologically or neuropathologically in great detail, while SDH and its curative surgery are known to cause SS. The distribution of the hypointensity areas on MRI was expanded bilaterally to the subtentorial areas of this patient, which was much more widespread than observed in typical SS after SDH. We speculate that the underlying ACP may expand the SS induced by SDH. Cp would accelerate iron export from the brain via the blood-cerebrospinal fluid (CSF) barrier, or CSF-brain barrier when excessive iron is loaded into the subarachnoid space.
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PMID:Superficial siderosis associated with aceruloplasminemia. Case report. 2460 34