Christmas factor
| Factor IXa | ||
|---|---|---|
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| according to PDB 1pfx | ||
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Existing structural data : 1CFH , 1CFI , 1EDM , 1IXA , 1MGX , 1NL0 , 1RFN , 2WPH , 2WPI , 2WPJ , 2WPK , 2WPL , 2WPM , 3KCG , 3LC3 , 3LC5 , 4YZU , 4Z0K , 4ZAE |
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| Properties of human protein | ||
| Mass / length primary structure | 380 = 145 + 235 amino acids | |
| Secondary to quaternary structure | Heterodimer | |
| Cofactor | Ca 2+ , phospholipids, factor VIIIa | |
| Precursor | Factor IX | |
| Identifier | ||
| Gene names | F9 ; FIX; GLA domain; HEMB; MGC129641; MGC129642; PTC | |
| External IDs | ||
| Drug information | ||
| ATC code | B02 BD04 | |
| DrugBank | DB00100 | |
| Drug class | Antihemorrhagics | |
| Enzyme classification | ||
| EC, category | 3.4.21.22 , serine protease | |
| MEROPS | S01.214 | |
| Substrate | Arg - + - Ile in factor X | |
| Products | Factor Xa | |
| Occurrence | ||
| Homology family | Serine protease | |
| Parent taxon | Euteleostomi | |
| Orthologue | ||
| human | House mouse | |
| Entrez | 2158 | 14071 |
| Ensemble | ENSG00000101981 | ENSMUSG00000031138 |
| UniProt | P00740 | P16294 |
| Refseq (mRNA) | NM_000133 | NM_001305797 |
| Refseq (protein) | NP_000124 | NP_001292726 |
| Gene locus | Chr X: 139.53 - 139.56 Mb | Chr X: 60 - 60.03 Mb |
| PubMed search | 2158 |
14071
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The Christmas factor (also antihemophilic globulin B or factor IX ) is a coagulation factor for blood clotting with an enzyme function ( serine proteinase ). The synthesis of the Christmas factor found in the liver instead and requires vitamin K . The protein has a molar mass of about 68 kDa and belongs to the group of β-globulins .
genetics
The gene that codes for the Christmas factor is located in humans on the X chromosome , gene locus q27.1–27.2.
function
The Christmas factor is activated by factor XIa ( plasma thromboplastin antecedent ) and / or factor VIIa (proconvertin). When activated, the Christmas factor in turn activates factor X ( Stuart-Prower factor ) through hydrolysis .
The Christmas factor requires calcium , phospholipids and factor VIII (antihemophilic globulin A) as a coenzyme .
Diseases
A congenital deficiency of the Christmas factor is present in a hemophilia ( haemophilia B ). Acquired deficiencies occur with a vitamin K deficiency or the presence of autoantibodies against the Christmas factor (e.g. lupus erythematosus ).
The Christmas factor can be substituted in the form of factor concentrates as an infusion . These contain the factor in purified and concentrated form, which is obtained from blood plasma by plasma fractionation . Determining the Christmas factor activity can provide diagnostic information about the presence of a deficiency.
history
The Christmas factor was named after Stephen Christmas, the five-year-old patient who was first described as having hemophilia B and its inheritance pattern in 1952. The fact that the publication in the British Medical Journal appeared in the Christmas edition of December 27th was probably more of a coincidence and in any case not decisive for the naming.
swell
- PL Giangrande: Six characters in search of an author: the history of the nomenclature of coagulation factors. In: Br J Haematol . 121, 2003, pp. 703-712. PMID 12780784 .
- RA Biggs, AS Douglas, RG MacFarlane, JV Dacie, WR Pittney, C. Merskey, JR O'Brien: Christmas disease: a condition previously mistaken for haemophilia. In: Br Med J . 2, 1952, pp. 1378-1382. PMID 12997790 .
Web links
- Christmas factor. In: Online Mendelian Inheritance in Man . (English)
- Interactive tutorial about the structure of the Christmas factor at PDBe