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Artykuły w czasopismach na temat "Iron – Physiological transport"
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Duck, Kari A., i James R. Connor. "Iron uptake and transport across physiological barriers". BioMetals 29, nr 4 (25.07.2016): 573–91. http://dx.doi.org/10.1007/s10534-016-9952-2.
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Li, Shuang, Yihu Yang i Weikai Li. "Human ferroportin mediates proton-coupled active transport of iron". Blood Advances 4, nr 19 (2.10.2020): 4758–68. http://dx.doi.org/10.1182/bloodadvances.2020001864.
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Abstract As the sole iron exporter in humans, ferroportin controls systemic iron homeostasis through exporting iron into the blood plasma. The molecular mechanism of how ferroportin exports iron under various physiological settings remains unclear. Here we found that purified ferroportin incorporated into liposomes preferentially transports Fe2+ and exhibits lower affinities of transporting other divalent metal ions. The iron transport by ferroportin is facilitated by downhill proton gradients at the same direction. Human ferroportin is also capable of transporting protons, and this activity is tightly coupled to the iron transport. Remarkably, ferroportin can conduct active transport uphill against the iron gradient, with favorable charge potential providing the driving force. Targeted mutagenesis suggests that the iron translocation site is located at the pore region of human ferroportin. Together, our studies enhance the mechanistic understanding by which human ferroportin transports iron and suggest that a combination of electrochemical gradients regulates iron export.
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Venkidusamy, Krishnaveni, Mallavarapu Megharaj, Uwe Schröder, Fouad Karouta, S. Venkata Mohan i Ravi Naidu. "Electron transport through electrically conductive nanofilaments in Rhodopseudomonas palustris strain RP2". RSC Advances 5, nr 122 (2015): 100790–98. http://dx.doi.org/10.1039/c5ra08742b.
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The study demonstrates the physiological induction of electrically conductive nanofilaments from a metabolically versatile, iron(iii) respiring, photosynthetic bacteriumRhodopseudomonas palustrisstrain RP2.
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Li, Jingwei, i J. A. Cowan. "Glutathione-coordinated [2Fe–2S] cluster: a viable physiological substrate for mitochondrial ABCB7 transport". Chemical Communications 51, nr 12 (2015): 2253–55. http://dx.doi.org/10.1039/c4cc09175b.
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Zhang, Xinxin, Di Zhang, Wei Sun i Tianzuo Wang. "The Adaptive Mechanism of Plants to Iron Deficiency via Iron Uptake, Transport, and Homeostasis". International Journal of Molecular Sciences 20, nr 10 (16.05.2019): 2424. http://dx.doi.org/10.3390/ijms20102424.
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Iron is an essential element for plant growth and development. While abundant in soil, the available Fe in soil is limited. In this regard, plants have evolved a series of mechanisms for efficient iron uptake, allowing plants to better adapt to iron deficient conditions. These mechanisms include iron acquisition from soil, iron transport from roots to shoots, and iron storage in cells. The mobilization of Fe in plants often occurs via chelating with phytosiderophores, citrate, nicotianamine, mugineic acid, or in the form of free iron ions. Recent work further elucidates that these genes’ response to iron deficiency are tightly controlled at transcriptional and posttranscriptional levels to maintain iron homeostasis. Moreover, increasing evidences shed light on certain factors that are identified to be interconnected and integrated to adjust iron deficiency. In this review, we highlight the molecular and physiological bases of iron acquisition from soil to plants and transport mechanisms for tolerating iron deficiency in dicotyledonous plants and rice.
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Hunt, Janet R. "Dietary and Physiological Factors That Affect the Absorption and Bioavailability of Iron". International Journal for Vitamin and Nutrition Research 75, nr 6 (1.11.2005): 375–84. http://dx.doi.org/10.1024/0300-9831.75.6.375.
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Iron deficiency, a global health problem, impairs reproductive performance, cognitive development, and work capacity. One proposed strategy to address this problem is the improvement of dietary iron bioavailability. Knowledge of the molecular mechanisms of iron absorption is growing rapidly, with identification of mucosal iron transport and regulatory proteins. Both body iron status and dietary characteristics substantially influence iron absorption, with minimal interaction between these two factors. Iron availability can be regarded mainly as a characteristic of the diet, but comparisons between human studies of iron availability for absorption require normalization for the iron status of the subjects. The dietary characteristics that enhance or inhibit iron absorption from foods have been sensitively and quantitatively determined in human studies employing iron isotopes. People with low iron status can substantially increase their iron absorption from diets with moderate to high availability. But while iron supplementation and fortification trials can effectively increase blood indices of iron status, improvements in dietary availability alone have had minimal influence on such indices within several weeks or months. Plentiful, varied diets are the ultimate resolution to iron deficiency. Without these, more modest food-based approaches to human iron deficiency likely will need to be augmented by dietary iron fortification.
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Gulec, Sukru, Gregory J. Anderson i James F. Collins. "Mechanistic and regulatory aspects of intestinal iron absorption". American Journal of Physiology-Gastrointestinal and Liver Physiology 307, nr 4 (15.08.2014): G397—G409. http://dx.doi.org/10.1152/ajpgi.00348.2013.
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Iron is an essential trace mineral that plays a number of important physiological roles in humans, including oxygen transport, energy metabolism, and neurotransmitter synthesis. Iron absorption by the proximal small bowel is a critical checkpoint in the maintenance of whole-body iron levels since, unlike most other essential nutrients, no regulated excretory systems exist for iron in humans. Maintaining proper iron levels is critical to avoid the adverse physiological consequences of either low or high tissue iron concentrations, as commonly occurs in iron-deficiency anemia and hereditary hemochromatosis, respectively. Exquisite regulatory mechanisms have thus evolved to modulate how much iron is acquired from the diet. Systemic sensing of iron levels is accomplished by a network of molecules that regulate transcription of the HAMP gene in hepatocytes, thus modulating levels of the serum-borne, iron-regulatory hormone hepcidin. Hepcidin decreases intestinal iron absorption by binding to the iron exporter ferroportin 1 on the basolateral surface of duodenal enterocytes, causing its internalization and degradation. Mucosal regulation of iron transport also occurs during low-iron states, via transcriptional (by hypoxia-inducible factor 2α) and posttranscriptional (by the iron-sensing iron-regulatory protein/iron-responsive element system) mechanisms. Recent studies demonstrated that these regulatory loops function in tandem to control expression or activity of key modulators of iron homeostasis. In health, body iron levels are maintained at appropriate levels; however, in several inherited disorders and in other pathophysiological states, iron sensing is perturbed and intestinal iron absorption is dysregulated. The iron-related phenotypes of these diseases exemplify the necessity of precisely regulating iron absorption to meet body demands.
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Kitphati, Worawan, Patchara Ngok-ngam, Sukanya Suwanmaneerat, Rojana Sukchawalit i Skorn Mongkolsuk. "Agrobacterium tumefaciens fur Has Important Physiological Roles in Iron and Manganese Homeostasis, the Oxidative Stress Response, and Full Virulence". Applied and Environmental Microbiology 73, nr 15 (1.06.2007): 4760–68. http://dx.doi.org/10.1128/aem.00531-07.
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ABSTRACT In Agrobacterium tumefaciens, the balance between acquiring enough iron and avoiding iron-induced toxicity is regulated in part by Fur (ferric uptake regulator). A fur mutant was constructed to address the physiological role of the regulator. Atypically, the mutant did not show alterations in the levels of siderophore biosynthesis and the expression of iron transport genes. However, the fur mutant was more sensitive than the wild type to an iron chelator, 2,2′-dipyridyl, and was also more resistant to an iron-activated antibiotic, streptonigrin, suggesting that Fur has a role in regulating iron concentrations. A. tumefaciens sitA, the periplasmic binding protein of a putative ABC-type iron and manganese transport system (sitABCD), was strongly repressed by Mn2+ and, to a lesser extent, by Fe2+, and this regulation was Fur dependent. Moreover, the fur mutant was more sensitive to manganese than the wild type. This was consistent with the fact that the fur mutant showed constitutive up-expression of the manganese uptake sit operon. FurAt showed a regulatory role under iron-limiting conditions. Furthermore, Fur has a role in determining oxidative resistance levels. The fur mutant was hypersensitive to hydrogen peroxide and had reduced catalase activity. The virulence assay showed that the fur mutant had a reduced ability to cause tumors on tobacco leaves compared to wild-type NTL4.
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Froschauer, Elisabeth M., Nicole Rietzschel, Melanie R. Hassler, Markus Binder, Rudolf J. Schweyen, Roland Lill, Ulrich Mühlenhoff i Gerlinde Wiesenberger. "The mitochondrial carrier Rim2 co-imports pyrimidine nucleotides and iron". Biochemical Journal 455, nr 1 (13.09.2013): 57–65. http://dx.doi.org/10.1042/bj20130144.
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Mitochondrial iron uptake is of key importance both for organelle function and cellular iron homoeostasis. The mitochondrial carrier family members Mrs3 and Mrs4 (homologues of vertebrate mitoferrin) function in organellar iron supply, yet other low efficiency transporters may exist. In Saccharomyces cerevisiae, overexpression of RIM2 (MRS12) encoding a mitochondrial pyrimidine nucleotide transporter can overcome the iron-related phenotypes of strains lacking both MRS3 and MRS4. In the present study we show by in vitro transport studies that Rim2 mediates the transport of iron and other divalent metal ions across the mitochondrial inner membrane in a pyrimidine nucleotide-dependent fashion. Mutations in the proposed substrate-binding site of Rim2 prevent both pyrimidine nucleotide and divalent ion transport. These results document that Rim2 catalyses the co-import of pyrimidine nucleotides and divalent metal ions including ferrous iron. The deletion of RIM2 alone has no significant effect on mitochondrial iron supply, Fe–S protein maturation and haem synthesis. However, RIM2 deletion in mrs3/4Δ cells aggravates their Fe–S protein maturation defect. We conclude that under normal physiological conditions Rim2 does not play a significant role in mitochondrial iron acquisition, yet, in the absence of the main iron transporters Mrs3 and Mrs4, this carrier can supply the mitochondrial matrix with iron in a pyrimidine-nucleotide-dependent fashion.
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Meynard, Delphine, Jodie L. Babitt i Herbert Y. Lin. "The liver: conductor of systemic iron balance". Blood 123, nr 2 (9.01.2014): 168–76. http://dx.doi.org/10.1182/blood-2013-06-427757.
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Abstract Iron is a micronutrient essential for almost all organisms: bacteria, plants, and animals. It is a metal that exists in multiple redox states, including the divalent ferrous (Fe2+) and the trivalent ferric (Fe3+) species. The multiple oxidation states of iron make it excellent for electron transfer, allowing iron to be selected during evolution as a cofactor for many proteins involved in central cellular processes including oxygen transport, mitochondrial respiration, and DNA synthesis. However, the redox cycling of ferrous and ferric iron in the presence of H2O2, which is physiologically present in the cells, also leads to the production of free radicals (Fenton reaction) that can attack and damage lipids, proteins, DNA, and other cellular components. To meet the physiological needs of the body, but to prevent cellular damage by iron, the amount of iron in the body must be tightly regulated. Here we review how the liver is the central conductor of systemic iron balance and show that this central role is related to the secretion of a peptide hormone hepcidin by hepatocytes. We then review how the liver receives and integrates the many signals that report the body’s iron needs to orchestrate hepcidin production and maintain systemic iron homeostasis.
Rozprawy doktorskie na temat "Iron – Physiological transport"
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Granger, Julie. "Iron acquisition by heterotrophic marine bacteria". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0002/MQ44173.pdf.
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Maldonado-Pareja, Maria Teresa. "Iron acquisition by marine phytoplankton". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0022/NQ50215.pdf.
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Castelli, Joanne Maree. "Characterisation of putative transporters maintaining iron homeostasis in symbiotic soybeans". University of Western Australia. School of Biomedical, Biomolecular and Chemical Sciences, 2006. http://theses.library.uwa.edu.au/adt-WU2007.0020.
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[Truncated abstract] Nitrogen fixation is a feature of the symbiotic association between legumes and rhizobia, which occurs within the symbiosomes of root nodules and involves the conversion of atmospheric N2 to ammonia to be used by the plant in exchange for carbon compounds. Exchange of other nutrients is controlled by plant-synthesised proteins on the symbiosome membrane. Iron is a component of symbiotically important proteins, so is essential for nitrogen fixation. Low soil iron leads to decreased plant yields, whilst in other environments plants may accumulate iron to toxic levels. Knowledge of iron acquisition, transport and storage mechanisms is important to elucidate the role of iron transporters in the maintenance of iron homeostasis in the plant. This study provides evidence that iron has a profound effect in the Bradyrhizobium japonicum-Glycine max symbiosis on the development of the nodule, and on the development of the symbiotic soybean plant itself. cDNAs encoding four putative iron transporters in soybean; GmDmt1, GmYSL1, GmCCC1;1 and GmCCC1;2, were identified, isolated and characterised in this study. GmDmt1 is localised to the symbiosome membrane. Expression of GmDmt1 occurs in nodules, roots and leaves and increases in response to iron starvation. GmDmt1 rescues growth and enhances 55Fe(II) uptake in the iron transport deficient yeast strain fet3fet4, with uptake following Michaelis-Menten kinetics, resembling the situation in isolated symbiosomes. Competition experiments using fet3fet4 indicated that GmDmt1 is able to transport other divalent cations, including zinc, copper and manganese, and is also able to complement a zinc transport deficient yeast mutant. ... These results suggest the divalent metal transporter GmDmt1, the putative iron chelate transporter GmYSL1 and the putative vacuolar iron transporters GmCCC1;1 and GmCCC1;2 act together to maintain iron homeostasis in symbiotic soybeans. The possible interactions and regulation of these proteins and their roles in the acquisition, transport and utilisation of iron in symbiotic soybeans are discussed.
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Adly, Carol. "The role of iron in the ecology and physiology of marine bacteria /". Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=97884.
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Despite being abundant in the earth's crust, the concentration of Fe in many oceanic regions is so low that it is limiting to the growth of photosynthetic plankton. Heterotrophic bacteria play key roles in the oceanic cycling of carbon and nutrients, but it is unclear whether they can be Fe-deficient in nature, or what possible effects Fe-deficiency might have on their ecology and physiology. In chapter 1, I investigated the response of a natural bacterial community to a mesoscale Fe-enrichment experiment in the northeast subarctic Pacific. The addition of Fe to surface waters caused a rapid stimulation of bacterial growth and production, and induced the organic Fe uptake systems of bacteria. These findings suggest that bacteria responded directly to increased Fe availability, and may be Fe-deficient in situ. In chapter 2, I examined the effects of Fe-deficiency on the coupled processes of carbon catabolism and adenosine triphosphate (ATP) production in cultures of the marine bacterium Pseudoalteromonas haloplanktis. In Fe-limited cells, Fe-dependent oxidative pathways of ATP production were downregulated, leading to an intracellular energy deficit. Thus, by altering carbon metabolism and energy acquisition of heterotrophic bacteria, Fe may affect the cycling of carbon in parts of the sea.
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Nodwell, Lisa M. "Inorganic colloidal iron use by marine mixotrophic phytoplankton". Thesis, McGill University, 2000. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=30826.
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Three species of photosynthetic flagellates capable of phagotrophy (mixotrophic species) were tested for their abilities to use inorganic iron colloids for growth. Ochromonas sp., Chrysochromulina ericina (a coastal strain) and C. ericina (an oceanic strain) were grown in iron-free seawater supplemented with 1 muM goethite, hematite, magnetite/maghemite or ferrihydrite (90°) in the presence and absence of desferrioxamme B, an iron-binding siderophore. Both strains of Chrysochromulina grew at 35--70% of their maximum rates with goethite, hematite, and magnetite/maghemite, but were unable to use ferrihydrite. Ochromonas, however, grew well with ferrihydrite, but could not use any of the other forms. All the flagellates were able to acquire iron from ingested bacteria. Diatoms that were known only to take up dissolved forms of iron, Thalassiosira oceanica (clone 1003) and T. pseudonana (clone 3H), were unable to use any of the colloids tested. The mechanism of iron acquisition by the flagellates appeared to involve ingestion of the iron colloids as DFB had no effect on colloidal iron availability and bacteria resident in the cultures were unable to use the iron contained in the colloids. Variations in the size of the colloids were hypothesized to account for differences in their availability, independent of colloid chemical stability. The results provide the first strong evidence for direct utilization (i.e. without prior dissolution) of colloidal iron by mixotrophic phytoplankton and document a new pathway of iron acquisition that may be important for their survival in low-iron waters of the sea.
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Lin, Xiaohui, i 林晓晖. "Molecular analysis of an iron transporter gene of Burkholderia speciesMBA4". Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B4218194X.
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Shawki, Ali. "The Functional Properties and Intestinal Role of the H+-Coupled Divalent Metal-Ion Transporter 1, DMT1". University of Cincinnati / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1448037106.
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Hackett, Sara. "Magneto-chemical speciation of pathogenic iron deposits in thalassaemia and malaria". University of Western Australia. School of Physics, 2008. http://theses.library.uwa.edu.au/adt-WU2008.0205.
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[Truncated abstract] Iron is essential to most biological systems. Under pathological conditions affecting the iron metabolic pathway, iron can be deposited in the tissue in various forms. The work presented in this thesis has exploited the relationship between the magnetic and the chemical properties of tissue iron deposits to further understanding of two major pathologies, the haemoglobinopathies termed thalassaemias and the malaria parasite Plasmodium falciparum, both amongst the most common health concerns in tropical countries. The iron-specific magnetic susceptibilities ¿Fe for spleen tissue samples from 7 transfusion dependent ß-thalassaemia (ß-thal) patients and 11 non-transfusion dependent ß-thalassaemia/Haemoglobin E (ß/E) patients were measured at 37°C. Both groups of patients were iron loaded with no significant difference in the distribution of spleen iron concentrations between the two groups. There was a significant difference between the mean ¿Fe of the spleen tissue from each group. The ß/E patients had a higher mean (± standard deviation) spleen ¿Fe (1.55 ± 0.23 × 10-6 m3.kgFe -1) than the ß-thal patients (1.16 ± 0.25 × 10-6 m3.kgFe -1). Correlations were observed between ¿Fe of the spleen tissue and the fraction of magnetic hyperfine split sextet in the 57Fe Mössbauer spectra of the tissues at 78 K (Spearman rank order correlation ¿ = -0.54, p = 0.03) and between ¿Fe of the spleen tissue and the fraction of doublet in the spectra at 5 K (¿ = 0.58, p = 0.02) indicating that ¿Fe of the spleen tissue is related to the chemical speciation of the iron 2 deposits in the tissue. The biological variability of the iron-specific magnetic susceptibility of the tissue iron examined would contribute a random uncertainty of 19% to magnetic susceptibility based non-invasive measurements of tissue iron concentration. ... Magnetic susceptibility measurements were also performed on malaria parasitised red blood cells. In vitro cultures of P. falciparum were magnetically enriched up to 61-fold using high field gradient magnetic separation columns, and the magnetic susceptibility of cell contents was directly measured. Forms of haem iron were quantified spectroscopically. Further fractionations were performed such that, by controlling the fluid velocity through the column, cells with more than a critical amount of paramagnetic 3 iron were preferentially extracted. A chloroquine-sensitive (CQS) laboratory strain of parasites converted approximately 60% of host cell haem iron to haemozoin and this product was the primary source of the increase in cell magnetic susceptibility. The volumetric magnetic susceptibility of the magnetically enriched cells was found to be 0.15 ± 0.03 × 10-7 relative to the suspension medium, accounting for the enrichment of mature parasites. Comparisons of fractionation samples of two pairs of CQS and chloroquine resistant (CQR) strains showed enrichment of mature parasites was significantly greater in the CQS than the CQR strains. The results suggest the possibility of using magnetic separation columns in identifying CQR strains of P. falciparum, potentially in a diagnostic or research setting. The study also underlines the need to identify and quantify the forms of iron in CQR and CQS parasite strains as the fate of haem iron will have implications in understanding the mechanisms of chloroquine resistance.
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Thomas, Carla. "The validation and use of the rat intestinal epithelial cell line 6 (IEC-6) to study the role of ferroportin1 and divalent metal transporter 1 in the uptake of iron from Fe(II) and Fe(III)". University of Western Australia. Physiology Discipline Group, 2003. http://theses.library.uwa.edu.au/adt-WU2004.0019.
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[Formulae and special characters can only be approximated here. Please see the pdf version of the abstract for an accurate reproduction.] Iron is vital for almost all living organisms by participating in a wide variety of metabolic processes, including oxygen transport, DNA synthesis, and electron transport. However, iron concentrations in body tissues must be tightly regulated because excessive iron leads to tissue damage, as a result of formation of free radicals. In mammals since no controlled means of eliminating unwanted iron has evolved, body iron balance is maintained by alterations in dietary iron intake. This occurs in the duodenum where most dietary iron is absorbed. Absorption involves at least two steps, uptake of iron from the intestinal lumen and then its transport into the body, processes that occur at the apical and basal membranes of enterocytes, respectively. In chapter one of this thesis the background information relevant to iron absorption is described. Despite numerous studies, the role of these proteins in iron absorption remains unclear, partly because many studies have reported them in non-enterocyte cell lines where the expression of the proteins involved in iron absorption is unlikely and therefore the physiological significance of the findings uncertain. Therefore, the study of iron absorption would value from additional cell lines of intestinal origin being used, preferably derived from a species used to comprehensively study this process in vivo, namely the rat. Validation of such a model would enable comparisons to be made from a molecular level to its relevance in the whole organism. In chapter 3 of this thesis, the rat intestinal cell line 6 (IEC-6) was examined as a model of intestinal iron transport. IEC-6 cells expressed many of the proteins involved in iron absorption, but not the ferrireductase Dcytb, sucrase or αvβ3 integrin. In addition, in IEC-6 cells the expression of the apical transporter divalent metal transporter 1 (DMT1), the iron storage protein ferritin, the uptake of Fe(II) and Fe(III) were regulated by cellular iron stores as is seen in vivo. This suggests that IEC-6 cells are of a lower villus enterocyte phenotype. Presented in chapter 4 is the study of the uptake of iron from Fe(II):ascorbate and Fe(III):citrate by IEC-6 cells in the presence of a blocking antibody to the putative basolateral transporter ferroportin1 and of colchicine and vinblastine, different pHs, and over-expression of DMT1. It was shown that optimal Fe(II) uptake required a low extracellular pH and was dependent on DMT1. Uptake of Fe(III) functioned optimally at a neutral pH, did not require surface ferrireduction, and was increased during over-expression of DMT1. These observations suggest that intravesicular ferrireduction takes place before transport of Fe(II) to the cytoplasm by DMT1. This pathway was not blocked by a functional antibody against αvβ3 integrin but was inhibited by competition with unlabeled iron citrate or citrate alone. Surprisingly, a functional antibody against ferroportin1 had no effect on efflux but significantly reduced (p<0.05) uptake of Fe(II) by 40-50% and Fe(III) by 90%, indicating two separate pathways for the uptake of iron from Fe(II)-ascorbate and from Fe(III)-citrate in IEC-6 cells. Presented in chapter 5 is the development and validation of a technique for the removal of freshly isolated enterocytes from the rat duodenum and their use to study iron transport processes that enabled comparisons to be made between these cells, IEC-6 cells and the human enterocyte cell line Caco-2 cells. In chapter 6 a blocking antibody to ferroportin1 was shown to inhibit uptake of Fe(II) but not release of iron in freshly isolated duodenal enterocytes from rats and Caco-2 cells supporting the findings obtained with IEC-6 cells described in chapter 4. Fe(II) uptake was reduced only when the antibody was in contact with the apical membrane indicating its expression at the microvillus membrane. Confirming this, ferroportin1 was shown along the microvillus membrane of Caco-2 cells, in enriched microvillus membrane preparations and in enterocytes of duodenum tissue of rats where it co-localised with lactase. The significant findings to emerge from this thesis are that the IEC-6 cell is a valid model to study iron absorption producing results consistent with those found in freshly isolated enterocytes and in human enterocyte-like cells. In particular, ferroportin1 functions in the uptake of iron at the apical membrane possibly by modulating surface binding of Fe(II) to DMT1 or the activity of DMT1. In addition to this in Fe(II) uptake from Fe(III) ferroportin1 may also affect the number of Fe(III): citrate binding sites. Preliminary studies further characterizing the function of ferroportin1 at the apical membrane and at intracellular sites of IEC-6 cells along with integration of these data are discussed in chapter 7.
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Luck, Shelley Narelle. "The SRL pathogenicity island of Shigella flexneri 2a YSH6000". Monash University, Dept. of Microbiology, 2003. http://arrow.monash.edu.au/hdl/1959.1/9549.
Pełny tekst źródłaKsiążki na temat "Iron – Physiological transport"
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Přemysl, Poňka, Schulman Herbert M i Woodworth Robert C, red. Iron transport and storage. Boca Raton: CRC Press, 1990.
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Iron transport in bacteria. Washington, DC: ASM Press, 2005.
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Astrid, Sigel, i Sigel Helmut, red. Iron transport and storage in microorganisms, plants, and animals. New York: Marcel Dekker, 1998.
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(Editor), Astrid Sigel, i Helmut Sigel (Editor), red. Metal Ions in Biological Systems. Marcel Dekker, 1998.
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(Editor), Jorge H. Crosa, Alexandra R. Mey (Editor) i Shelley M. Payne (Editor), red. Iron Transport In Bacteria: Molecular Genetics, Biochemistry, And Role In Pathogenicity And Ecology. ASM Press, 2004.
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G, Burns Richard, i Dick Richard P. 1950-, red. Enzymes in the environment: Activity, ecology, and applications. New York: Marcel Dekker, 2002.
Znajdź pełny tekst źródłaCzęści książek na temat "Iron – Physiological transport"
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Ho, C., i H. W. Kim. "Design of Novel Hemoglobins". W Biological NMR Spectroscopy. Oxford University Press, 1997. http://dx.doi.org/10.1093/oso/9780195094688.003.0013.
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Human normal adult hemoglobin (Hb) A, the oxygen carrier of blood, is a tetrameric protein consisting of two α chains of 141 amino acid residues each and two β chains of 146 amino acid residues each. Each Hb chain contains a heme group which is an iron complex of protoporphyrin IX. Under physiological conditions, the heme-iron atoms of Hb remain in the ferrous state. In the absence of oxygen, the four heme-irom atoms in Hb A are in the highspin ferrous state [Fe(II)] with four unpaired electrons each. Each of the four heme-iron atoms in Hb A can combine with an O2 molecule to give oxyhemoglobin (HbO2) in which the iron atom is in a low-spin, diamagnetic ferrous state. The oxygen binding of Hb exhibits sigmoidal behavior, with an overall association constant expression giving a greater than first-power dependence on the concentration of O2. Thus, the oxygenation of Hb is a cooperative process, such that when one O2 is bound, succeeding O2 molecules are bound more readily. Hb is an allosteric protein, i.e., its functional properties are regulated by a number of metabolites [such as hydrogen ions, chloride, carbon dioxide, 2,3-diphosphoglycerate (2,3-DPG)] other than its ligand, O2. It has been used as a model for allosteric proteins, and indeed, hemoglobins of vertebrates are among the most extensively studied allosteric proteins. Their allosteric properties are physiologically important in optimizing O2 transport by erythrocytes. The large number of mutant forms of Hb available provides an array of structural alterations with which to correlate effects on function. For details, see DickersonandGeis (1983), Bunnand Forget (1986), Ho (1992), Ho and Perussi (1994). There are two types of contacts between the α and β subunits of Hb (Perutz, 1970; Dickerson and Geis, 1983). The α1β1 (or α2 β2) contacts, involving B, G, and H helices, and GH corners, are called packing contacts. These contacts remain unchanged and hold the dimer together even when there is a change in the ligation state of the heme.