Transferrin | ||
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| PDB rendering based on 1a8e. The Protein Data Bank ( PDB) is a repository for 3-D structural data of Proteins and Nucleic acids These data typically obtained by X-ray crystallography | ||
| Available structures: 1a8e, 1a8f, 1b3e, 1bp5, 1btj, 1d3k, 1d4n, 1dtg, 1fqe, 1fqf, 1jqf, 1n7w, 1n7x, 1n84, 1oqg, 1oqh, 1ryo, 1suv, 2hau, 2hav, 2o7u, 2o84 | ||
| Identifiers | ||
| Symbol(s) | TF; DKFZp781D0156; PRO1557; PRO2086 | |
| External IDs | OMIM: 190000 MGI: 98821 HomoloGene: 68153 | |
| RNA expression pattern | ||
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| Orthologs | ||
| Human | Mouse | |
| Entrez | 7018 | 22041 |
| Ensembl | ENSG00000091513 | ENSMUSG00000032554 |
| Uniprot | P02787 | Q3UBW7 |
| Refseq | NM_001063 (mRNA) NP_001054 (protein) | NM_133977 (mRNA) NP_598738 (protein) |
| Location | Chr 3: 134.95 - 134.98 Mb | Chr 9: 103.07 - 103.09 Mb |
| Pubmed search | [1] | [2] |
Transferrin is a blood plasma protein for iron ion delivery. The Human Genome Organisation (HUGO is an organization involved in the Human Genome Project, a project about mapping the human genome The Mouse Genome Informatics (MGI website is run by The Jackson Laboratory. HomoloGene, a tool of the National Center for Biotechnology Information (NCBI is a system for automated detection of homologs (similarity attributable to descent The Entrez Global Query Cross-Database Search System is a powerful Federated search engine or Web portal that allows users to search many discrete Health sciences Ensembl is a joint scientific project between the European Bioinformatics Institute and the Wellcome Trust Sanger Institute, which was launched in 1999 in response to the imminent UniProt is the uni versal prot ein resource a central repository of Protein data created by combining Swiss-Prot, TrEMBL PubMed is a free search engine for accessing the MEDLINE database of citations and abstracts of biomedical research articles Blood plasma is the Liquid component of Blood, in which the Blood cells are suspended Proteins are large Organic compounds made of Amino acids arranged in a linear chain and joined together by Peptide bonds between the Carboxyl Iron (ˈаɪɚn is a Chemical element with the symbol Fe (ferrum and Atomic number 26 An ion is an Atom or Molecule which has lost or gained one or more Valence electrons giving it a positive or negative electrical charge Transferrin is a glycoprotein, which binds iron very tightly but reversibly. Not to be confused with Peptidoglycan. Glycoproteins are proteins that contain Oligosaccharide chains ( Glycans) covalently attached Although iron bound to transferrin is less than 0. 1% (4 mg) of the total body iron, dynamically it is the most important iron pool, with the highest rate of turnover (25 mg/24 h). Transferrin has a molecular weight of around 80 kiloDaltons and contains 2 specific high affinity Fe(III) binding sites. The affinity of transferrin for Fe(III) is extremely high (10^23 M^-1 at pH 7. 4) but decreases progressively with decreasing pH below neutrality.
When not bound to iron, it is known as "apotransferrin" (see also apoprotein).
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Transport mechanism
When a transferrin protein loaded with iron encounters a transferrin receptor on the surface of a cell (importantly, to erythroid precursors in the bone marrow), it binds to it and is consequently transported into the cell in a vesicle. Transferrin receptor (TfR is a Carrier protein for Transferrin. The cell is the structural and functional unit of all known living Organisms It is the smallest unit of an organism that is classified as living and is often called A vesicle is a small bubble of liquid within a cell A more formal definition in Cell biology, would be that a vesicle is a relatively small intracellular membrane-enclosed The H+ ATPase of the cell will decrease the pH of the vesicle, causing transferrin to release its iron ions. The receptor with its ligand bound to it is then transported through the endocytic cycle back to the cell surface, ready for another round of iron uptake. Most animal cells take up portions of their surface Plasma membranes in a process called Endocytosis. Each transferrin molecule has the ability to carry two iron ions in the ferric form (Fe3+). Ferric is a term that means containing or having to do with Iron, derived from the Latin word ferrum, meaning "iron"
The gene coding for transferrin in humans is located in chromosome band 3q21. History See also History of genetics The existence of genes was first suggested by Gregor Mendel (1822-1884 who in the 1860s studied inheritance A chromosome is an organized structure of DNA and Protein that is found in cells. Research on king snakes by Dessauer and Zwiefel in 1981 revealed that the inheritance of transferrin is a codominant trait.
Medical professionals may check serum transferrin level in iron deficiency, hemochromatosis and other iron overload disorders. Haemochromatosis, also spelled hemochromatosis (see spelling differences) also called siderophilia In Medicine, iron overload disorders are Diseases caused by the accumulation of Iron in the body
Immune system
Transferrin is also associated with the innate immune system. Transferrin is found in the mucosa and binds iron, thus creating an environment low in free iron, where few bacteria are able to survive. The mucous membranes (or mucosae; singular mucosa) are linings of mostly endodermal origin covered in Epithelium, which are involved in The levels of transferrin decreases in inflammation[1], seeming contradictory to its function.
A decrease in the amount of transferrin would result in hemosiderin in the liver.
Other effects
The metal binding properties of transferrin have a great influence on the biochemistry of plutonium in humans. Transferrin has a bacteriocidal effect on bacteria, in that it makes Fe3+ unavailable to the bacteria.
Pathology
A deficiency is associated with atransferrinemia. Atransferrinemia, also called familial hypotransferrinemia, is an autosomal recessive Metabolic disorder in which there is an absence
See also
External links
References
- ^ Ritchie RF, Palomaki GE, Neveux LM, Navolotskaia O, Ledue TB, Craig WY (1999). Beta-2 transferrin is a Carbohydrate -free ( desialated) Isoform of Transferrin, which is almost only found in the Cerebrospinal fluid Transferrin receptor (TfR is a Carrier protein for Transferrin. Total iron-binding capacity is a medical laboratory test which measures the extent to which iron-binding sites in the serum can be saturated Transferrin saturation, measured as a percentage is a Medical laboratory value Medical Subject Headings ( MeSH) is a huge Controlled vocabulary (or metadata system for the purpose of indexing journal articles and books "Reference distributions for the negative acute-phase serum proteins, albumin, transferrin and transthyretin: a practical, simple and clinically relevant approach in a large cohort". J. Clin. Lab. Anal. 13 (6): 273-9. PMID 10633294.
Further reading
- Hershberger CL, Larson JL, Arnold B, et al. (1992). "A cloned gene for human transferrin. ". Ann. N. Y. Acad. Sci. 646: 140-54. PMID 1809186.
- Bowman BH, Yang FM, Adrian GS (1989). "Transferrin: evolution and genetic regulation of expression. ". Adv. Genet. 25: 1-38. PMID 3057819.
- Parkkinen J, von Bonsdorff L, Ebeling F, Sahlstedt L (2003). "Function and therapeutic development of apotransferrin. ". Vox Sang. 83 Suppl 1: 321-6. PMID 12617162.
Dictionary
transferrin
-noun
- (biochemistry) a glycoprotein, a beta globulin, in blood serum that combines with, and transports iron
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