Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P02794 (ferritin)
 17,525 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Among the wall-less mycoplasmas only a few species have been identified with a capsule at their cell surface. Mycoplasma penetrans is a recently identified mycoplasma with unique morphology, isolated from HIV-infected patients. Using transmission electron microscopy, it was found that M. penetrans is surrounded by capsular material 11 nm (strain GTU-54-6A1) to 30 nm (strain HF-2) thick, which can be stained with ruthenium red and labelled with cationized ferritin. The polysaccharide composition of this capsule was indicated by its staining with periodic acid-thiocarbohydrazide silver proteinate and the abolition of ruthenium red staining of the cell surface by neuraminidase treatment. In addition, proteinase K treatment of the M. penetrans cells resulted in removal of the capsule, suggesting that polypeptides may contribute in anchoring it to the membrane or in its stability. Two different types of glycosylated material were detected in mycoplasma extracts by SDS-PAGE and periodic acid-Schiff staining. The first component was a high-molecular-mass material, which was heat- and proteinase-K-labile and which probably constitutes the capsular polymer. The other component was a low-molecular-mass glycolipid fraction, which was proteinase-K-, heat- and EDTA-resistant. The identification of a capsule at the M. penetrans cell surface is of particular interest for a mycoplasma which has been shown to adhere to various host cells and to penetrate into their intracellular compartments. The capsule may have significance in the pathogenesis of disease associated with infection by this organism.
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PMID:Identification of two glycosylated components of Mycoplasma penetrans: a surface-exposed capsular polysaccharide and a glycolipid fraction. 961 99

Growth failure is commonly described in polytransfused thalassaemia major patients (Th) with or without growth hormone (GH) releasing hormone-GH axis impairment. We have investigated the efficacy of short-term recombinant GH (rhGH) therapy (Saizen [Serono] 0.1 IU/kg/day 6 evenings/week administered s.c. for 12 months) on growth and predicted final height in 28 (19M, 9F) regularly transfused Th with growth deficiency (aged 14.8 +/- 2.0 yr) on long term desferrioxamine s.c. therapy. All Th had no evidence of congestive heart failure, hypothyroidism or impaired glucose tolerance; in all patients the GH peak (evaluated during both insulin and clonidine test) was < or = 20 mIU/l; hypergonadotropic hypogonadism was excluded in Th with delayed puberty. At the start of therapy height age (HA)/bone age (BA) ratio was 0.92 +/- 0.12. Bone age delay was positively correlated to chronological age (CA), serum ferritin levels (mean of the last three years), the age at the start of chelation therapy, growth velocity calculated for CA during the last year; a positive correlation was also found between circulating IGF-I levels and age at the start of chelation therapy. After 1 year on rhGH therapy there was a significant increase of height calculated for CA (not for BA), of growth velocity calculated for both CA and BA and of circulating IGF-I levels; the HA variation/BA variation ratio was 1.85 +/- 1.71, without any significant difference between predicted final height at the start (-1.08 +/- 1.28 SDS) and at the end of rhGH therapy (-0.88 +/- 1.13). The variation of height calculated for CA was positively correlated to both CA and growth velocity during the last year before rhGH therapy (calculated for CA) and negatively to the height at the start (calculated for CA). There were no side effects and haematological parameters did not show significant changes. In conclusion, our data, obtained in a relatively large group of Th, confirm the emerging results of short-term (12 months) rhGH therapy on growth, as shown by the increase of both growth velocity and height calculated for CA. With regard to final height, although the mean variation of HA/variation of BA ratio was 1.85, no significant increase of the predicted final height was found between the start and the end of rhGH therapy. We are evaluating the effect of long-term rhGH therapy on growth in these patients.
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PMID:Short-term therapy with recombinant growth hormone in polytransfused thalassaemia major patients with growth deficiency. 1009 Nov 55

The ferritins were purified from liver homogenates of buffalo, camel, cattle, sheep and shark by thermal denaturation, ammonium sulphate fractionation, Sephacryl S-300 gel filtration and DEAE-blue gel affinity chromatography. The yield and iron content of affinity-purified liver ferritins ranged from 0.008 to 0.052 mg/g and 3.17% to 11.4% respectively. As they are glycoproteins, the ferritins contained variable amounts of neutral carbohydrates. Except for shark ferritin, the ferritins all exhibited immunological cross-reactivity with anti-buffalo liver ferritin and anti-horse spleen ferritin by immunodiffusion and immunoelectrophoresis. Gel electrophoresis, gel filtration and ultracentrifugal analysis indicated the presence of a monomeric ferritin in all cases. SDS-gel electrophoresis of shark ferritin gave a protein band of 18 kDa. Ovine, buffalo and bovine ferritin comprised two protein subunits, the H (20 and 21 kDa) and the L types (18 and 19 kDa). Oligomeric ferritin subunits with molecular weights of 27, 37 and 55 kDa were also found for bovine and buffalo ferritin. SDS-PAGE of camel ferritin revealed a complex pattern with four prominent bands of 61, 51, 44 and 39 kDa. Two fast-migrating components of 15 and 16 kDa were also found in the purified liver ferritins, including reference preparations. The PO4(3-)/Fe ratios of purified shark (0.10) and bovine ferritin (0.12) were similar to that of standard equine spleen ferritin (0.11). However, the ratio was higher in ovine (0.17), camel (0.22) and bovine (0.26) ferritins. The amino acid compositions, molecular weights and sedimentation coefficients of the different liver ferritins were similar.
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PMID:Purification and characterization of liver ferritins from different animal species. 1040 20

Ferritin from the liver of fresh, salt and brackish water fishes was purified by thermal denaturation of liver homogenate followed by ammonium sulphate fractionation and Sephacryl S-300 gel filtration. Yield and iron content of purified fish ferritins were 0.016-0.026 mg/g of wet tissue and 4-14%, respectively. The iron content of ferritins from marine and brackish species was higher than from fresh water species. The phosphate/iron ratio ranged from 0.5 to 1.8 and was higher than mammalian ferritins. The fish ferritins have 5-6% neutral carbohydrate. Native gel electrophoresis and molecular weight analysis revealed the presence of a monomeric ferritin. SDS-gel electrophoresis and immunoblotting showed a single protein band of 21 kDa suggesting the presence of similar sized subunits in the native structure of fish ferritins. Isoelectric focusing revealed microheterogeneity with five to seven bands of pI values between 4.1 and 7.0. Variations in the amino acid composition were observed. Proline and arginine were not detected in murrel and salmon species, respectively. High proline and low tyrosine contents were recorded for perch ferritin. Immunological studies by non-competitive indirect ELISA revealed varying degrees of cross-reactivity. Mammalian ferritins exhibited a moderate cross-reactivity with anti-fish ferritin. On the contrary, very low or no cross-reactivity was observed between fish ferritin and anti-mammalian ferritin. Ferritins from bony fishes such as murrel and rohu exhibited a high degree of cross-reactivity with anti-shark ferritin. However, a moderate cross-reactivity was observed between shark and anti-murrel ferritin. Ferritin from marine bony fishes, salmon and mackerel and perch (brackish) showed a low to very low cross-reactivity with both the antisera.
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PMID:Purification and characterization of fish liver ferritins. 1048 Dec 57

Growth retardation in children with thalassaemia major is multifactorial. We studied the growth hormone (GH) response to provocation by clonidine and glucagon, measured the circulating concentrations of insulin, insulin-like growth factor-I (IGF-I), IGF-binding protein-3 (IGFBP3), and ferritin, and evaluated the spontaneous nocturnal (12 h) GH secretion in prepubertal patients with thalassaemia and age-matched children with constitutional short stature (CSS) (height SDS < -2, but normal GH response to provocation). The anatomy of the hypothalamic pituitary area was studied in patients with abnormal GH secretion using MRI scanning. Children with thalassaemia had significantly lower peak GH response to provocation by clonidine and glucagon (8.8 +/- 2.3 micrograms/l and 8.2 +/- 3.1 micrograms/l respectively) than did controls (17.6 +/- 2.7 micrograms/l and 15.7 +/- 3.7 micrograms/l respectively). They had significantly decreased circulating concentrations of IGF-I and IGFBP3 (68.5 +/- 19 ng/ml and 1.22 +/- 0.27 mg/l respectively) compared to controls (153 +/- 42 ng/ml and 2.16 +/- 0.37 mg/l respectively). Seven of the thalassaemic children had a GH peak response of < 7 micrograms/l after provocation. Those with a normal GH response after provocation also had significantly lower IGF-I and IGFBP3 concentrations than controls. Analysis of their spontaneous nocturnal GH secretion revealed lower mean (2.9 +/- 1.77 micrograms/l) and integrated (2.53 +/- 1.6 micrograms/l) concentrations compared to controls (4.9 +/- 0.29 micrograms/l and 5.6 +/- 0.52 micrograms/l respectively). Five of them had mean nocturnal GH concentration < 2 micrograms/l and four had maximum nocturnal peak below 10 micrograms/l. These data denoted defective spontaneous GH secretion in some of these patients. MRI studies revealed complete empty sella (n = 2), marked diminution of the pituitary size (n = 4), thinning of the pituitary stalk (n = 3) with its posterior displacement (n = 2), and evidence of iron deposition in the pituitary gland and midbrain (n = 7) in those patients with defective GH secretion (n = 9). Serum ferritin concentration was correlated significantly with the circulating IGF-I (r = -0.47, p < 0.01) and IGFBP3 (r = -0.43, p < 0.01) concentrations. These data prove a high prevalence of defective GH secretion in thalassaemic children associated with structural abnormality of their pituitary gland.
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PMID:Spontaneous and provoked growth hormone (GH) secretion and insulin-like growth factor I (IGF-I) concentration in patients with beta thalassaemia and delayed growth. 1066 1

Our previous work showed that immunization of mice with Schistosoma japonicum (Sj) immature eggs induced significant immunity against fecundity and embryonation of the parasite. The Sj adult cDNA library was screened by sera from rabbits against Sj immature egg antigen (RASjIEA). The genes encoding molecules which may induce immunity against fecundity/embryonation were chosen for further cloning and expression. First of all, RASjIEA was absorbed with E. coli lysate to remove cross reactive antibodies. The cDNA library was then immunoscreened using the routine method. The resulted positive plaques were rescreened till individual clones were confirmed. Phagemids were obtained using in vivo excision. The positive clones were amplified using PCR. The sizes of the genes were determined by agarose gel electrophoresis. After DNA sequencing of the genes cloned, Gene bank was searched and six different genes were identified from a total of 102 positive clones. One of six identified genes, Sj ferritin (SjFer) was chosen to subclone into pGMC vector. According to DNA sequences of Sj Fer and MCS (multiple cloning site) of the vector, forward primer (Fer/GMC1) and reverse primer (Fer/GMC2) were designed and used to amplify Sj Fer by PCR. The Sj Fer cDNA and expression vector pGMC were digested with BamHI and XhoI. The digested cDNA and pGMC were ligased by T4 DNA ligase to construct a recombinant which was then used to transform E. coli strain ER2566. The fusion protein GMCSF-Sj Ferritin was expressed in insoluble form, the inclusion body. Pellets were harvested and resolved in Tris-HCl buffer containing 8M urea. GMCSF-Sj Ferritin was purified by affinity chromatography using Ni-NTA resin. The molecular weight was determined by SDS-PAGE. This study first reports the gene encoding S. japonicum ferritin as a new candidate for schistosome vaccine.
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PMID:[Schistosoma japonicum ferritin: cloning, nucleotide sequencing, expression, and purification]. 1068 50

Aluminum toxicity is well documented but the mechanism of action is poorly understood. In renal failure patients with aluminum overload, disturbances in iron metabolism leading to anemia are apparent. Few animal models, however, have been used to study the effects of dietary aluminum on iron metabolism. The purpose of this study was to determine if dietary aluminum exposure alters tissue iron and ferritin concentrations in the chick, as has been found in cultured human cells exposed to aluminum. Groups of day-old chicks were fed purified diets containing one of two levels of iron (control or high iron), and one of three levels of aluminum chloride in a 2 x 3 factorial design. Diets were consumed ad libitum for 1 week, then pair-feeding was initiated for 2 more weeks. A seventh group consumed a low iron diet ad libitum for comparative purposes. After the 3-week feeding period, samples of kidney, liver, and intestinal mucosa were analyzed for nonheme iron and ferritin concentrations by a colorimetric assay and SDS-PAGE, respectively. Results showed that dietary aluminum intake reduced iron stores in liver and intestine, but had no effect on nonheme iron levels in the kidney. Ferritin levels were reduced by aluminum intake in all tissues studied. The decreases in tissue ferritin levels were proportionately more than the decreases in tissue nonheme iron levels. This resulted in increased nonheme iron to ferritin ratios that amounted to as much as 140 and 525% in kidney and intestine, respectively. These findings are consistent with the interpretation that, in the growing chick, dietary aluminum can inhibit iron absorption, disrupt the regulation of tissue ferritin levels by iron, and potentially alter the compartmentalization and protective sequestration of iron within cells.
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PMID:Effect of dietary aluminum on tissue nonheme iron and ferritin levels in the chick. 1068 9

Toxic and carcinogenic free radical processes induced by drugs and other chemicals are probably modulated by the participation of available iron. To see whether endogenous iron was genetically variable in normal mice, the common strains C57BL/10ScSn, C57BL/6J, BALB/c, DBA/2, and SWR were examined for major differences in their hepatic non-heme iron contents. Levels in SWR mice were 3- to 5-fold higher than in the two C57BL strains, with intermediate levels in DBA/2 and BALB/c mice. Concentrations in kidney, lung, and especially spleen of SWR mice were also greater than those in C57BL mice. Non-denaturing PAGE of hepatic ferritin from all strains showed a major holoferritin band at approximately 600 kDa, with SWR mice having > 3-fold higher levels than C57BL strains. SDS PAGE showed a band of 22 kDa, mainly representing L-ferritin subunits. A trace of a subunit at 18 kDa was also detected in ferritin from SWR mice. The 18 kDa subunit and a 500 kDa holoferritin from which it originates were observed in all strains after parenteral iron overload, and there was no major variation in ferritin patterns. Although iron uptake studies showed no evidence for differential duodenal absorption between strains to explain the variation in basal iron levels, acquisition of absorbed iron by the liver was significantly higher in SWR mice than C57BL/6J. As with iron and ferritin contents, total iron regulatory protein (IRP-1) binding capacity for mRNA iron responsive element (IRE) and actual IRE/IRP binding in the liver were significantly greater in SWR than C57BL/6J mice. Cytosolic aconitase activity, representing unbound IRP-1, tended to be lower in the former strain. SWR mice were more susceptible than C57BL/10ScSn mice to the toxic action of diquat, which is thought to involve iron catalysis. If extrapolated to humans, the findings could suggest that some people might have the propensity for greater basal hepatic iron stores than others, which might make them more susceptible to iron-catalysed toxicity caused by oxidants.
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PMID:Genetic variation of basal iron status, ferritin and iron regulatory protein in mice: potential for modulation of oxidative stress. 1081 Apr 45

The production and characterization of recombinant mouse H- and L-ferritin chains from Escherichia coli are described. The proteins were efficiently expressed and purified with yields of 7-40 mg per liter of cell culture. They had the expected molecular mass and showed a physical stability analogous to that of the corresponding human ferritins. Mouse H- and L-ferritins had a very similar mobility on denaturing SDS-PAGE, but could be readily separated on nondenaturing PAGE because of the distinct slow mobility of mouse L-ferritin. Direct comparative experiments showed that mouse and human H-ferritins had the same iron incorporation activity, whereas mouse L-ferritin incorporated iron less efficiently than human L-ferritin. The difference was attributed to the substitution of a residue exposed on the cavity surface (Glu140 --> Lys) in mouse L-ferritin, a hypothesis confirmed by the finding that the mouse L-ferritin mutant Lys140-Glu incorporated iron as efficiently as human L-ferritin. Rabbit antisera elicited by the recombinant mouse ferritins were specific for the H- and L-chains and did not cross-react with the human ferritins. The antibodies and the derived specific ELISA assays allow the determination of H- and L-ferritins in mouse tissues.
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PMID:Functional and immunological analysis of recombinant mouse H- and L-ferritins from Escherichia coli. 1083 9

Camel kidney ferritin was isolated from a tissue homogenate by thermal denaturation, ammonium sulphate fractionation, Sephacryl S-300 gel filtration and DEAE-blue gel affinity chromatography. The yield and the iron and neutral carbohydrate contents were 0.012 mg/g wet tissue, 4.0% and 2.7%, respectively. The phosphate:iron ratio was 0.13, twofold lower than that reported for camel liver ferritin. Native gel electrophoresis revealed the presence of a monomeric ferritin. SDS gel electrophoresis and immunoblotting showed two types of subunits, heavy and light, contrary to the extensive heterogeneity observed in camel liver ferritin. In general, the tissue ferritins shared a similar amino acid composition. However, a twofold lower glycine and an eightfold higher arginine content were recorded for camel kidney ferritin. In addition, kidney ferritin had a relatively high content of glutamic acid. Cross-reactivity studies by Ouchterlony double diffusion and noncompetitive indirect ELISA revealed a distinct cross-reactivity between buffalo ferritin antiserum and camel liver ferritin, but camel liver ferritin showed only weak cross-reactivity.
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PMID:Camel kidney ferritin: isolation and partial characterization. 1086 47


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