Chemical Properties
Brown-red crystalline substance, soluble in water, insoluble in saturated ammonium sulfate solution. Commodity is four times crystalline product, suspended in saturated ammonium sulfate solution.
Uses
Tool for the study of protein synthesis and regulatory mechanisms.
Uses
Ferritin from human liver has been used as model protein in size-exclusion high-performance liquid chromatography technique and for synthetic nanopore translocation studies. It has also been used to test its effect on the susceptibility of shrimp (
Litopenaeus vannamei) to the white spot syndrome virus.
Uses
Ferritin, cationized from horse spleen has been used:
- to incubate amoebae (106) in the study, to determine whether trophozoites are able to take up ferritin and internalise this protein for their growth in axenic culture
- to determine phagosome-lysosome fusion by electron microscopy
- to label freshly excised chick optic tecta in serum free incubation medium
Definition
FERRITIN, HUMAN is a major iron storage protein found in the spleen, liver and intestinal mucosa of vertebrates. It consists of a protein shell surrounding a crystalline, hydrated iron oxide-phosphate core.
General Description
Ferritin, an iron-storage protein is usually present in the liver and spleen in mammals. Iron andferritinare distributed relatively same in the eye. Ferritin is made up of heavy and light chains.
Biochem/physiol Actions
Ferritin holds iron at its ferric state (Fe3+). The core of ferritinhas the capability to hold 4500 iron molecules. It is essential to store iron in vertebrates. Ferritinis also essential to store and transport iron in invertebrates. It plays a key role in dietary iron absorption.
Purification Methods
The purification of this major iron-binding protein is achieved by homogenisation in water and precipitation with ammonium sulfate, repeating the cycle of ultracentrifugation, and molecular sieve chromatography through a Sephadex 4B column. Isoelectric focusing reveals a broad spectrum of impurities which can be separated by ion-exchange chromatography on Sephadex A-25 and stepwise elution. [Konijn et al. Anal Biochem 144 423 1985.]
Description
Ferritin is a glycoprotein produced in Human Liver having a molecular mass of 440- 450kDa and pI of 5.5, which stores iron atoms in the ferric state. It is predominantly intracellular, where it forms an exchangeable pool of iron acting as an iron store. Ferritin level in serum is directly proportional to body iron stores and serum levels are an excellent indicator in monitoring iron status in anemia.
It can be used as a marker for inflammation and also used for monitoring and prediction of future events in coronary artery disease.
Background
Ferritin is the main intracellular iron storage protein in prokaryotes and eukaryotes. Ferritin’s major functions are the storage of iron in a soluble and nontoxic state and its release in a controlled fashion. An iron-containing protein complex is found mostly in the intestinal mucosa, spleen, and liver. Ferritin is composed of 24 subunits of the heavy and light chains. Variation in ferritin subunit composition may influence the rates of iron uptake and release in different tissues. Defects in the light chain ferritin gene are linked to a number of neurodegenerative diseases and hyperferritinemia-cataract syndrome. The genes that encode the light and heavy chains are on located different chromosomes. The light chain genes are in chromosome region 19q13.3-q13.4 whilst those for the heavy chain are in chromosome region 11q12-q13. Ferritin is shaped like a hollow sphere, inside which the iron is stored in the Fe(III) oxidation state. The iron is integrated in the mineral ferrihydrite, [FeO(OH)]8[FeO(H2PO4)], which is attached to the inner wall of the sphere. To release iron once the body needs it, the iron must be altered from the Fe(III) to the Fe(II) oxidation state. Subsequently, the iron leaves through channels in the spherical structure. Therefore, the structure of ferritin is tremendously important for the protein's ability to store and release iron in a controlled mode.
The amount of ferritin in the blood (serum ferritin level) is directly related to the amount of iron stored in the body. The body has a "buffer" against iron deficiency (if the blood has too little iron, ferritin can release more) and, to a lesser extent, iron overload (if the blood and tissues of the body have too much iron, ferritin can help store the excess iron).
