α-1 antitrypsin
| Α-1 antitrypsin | ||
|---|---|---|
|
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| Ribbon / surface model of the monomer according to PDB 1HP7 | ||
|
Existing structural data : 1atu , 1d5s , 1ezx , 1hp7 , 1iz2 , 1kct , 1oo8 , 1oph , 1psi , 1qlp , 1qmb , 2d26 , 7api , 8api , 9api |
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| Properties of human protein | ||
| Mass / length primary structure | 394 amino acids | |
| Secondary to quaternary structure | Homodimer | |
| Isoforms | 3 | |
| Identifier | ||
| Gene names | SERPINA1 ; PI; A1A; A1AT; AAT; MGC23330; MGC9222; PI1; PRO2275 | |
| External IDs | ||
| Drug information | ||
| ATC code | B02 AB02 | |
| DrugBank | DB00058 | |
| Drug class | Protease inhibitors | |
| Inhibitor classification | ||
| MEROPS | I04.001 | |
| Occurrence | ||
| Homology family | Serpin A1 | |
| Parent taxon | Creature | |
α 1 -antitrypsin ( AAT ) or α 1 -protease inhibitor (α 1 PI) is an acute phase protein that protects body tissue from enzymes involved in inflammatory processes .
description
AAT works by mainly inhibiting PMN elastase , but also trypsin and other serine proteases . If this inhibition fails due to a deficiency or a functionally restricted AAT, the elastase attacks, for example, the connective tissue of the lungs, which can lead to serious complications .
An increase in the α 1 -antitrypsin value occurs
- acute attacks of chronic inflammatory processes ,
- Tumors (especially bronchial carcinoma, see tumor markers ),
- Pregnancy or
- an estrogen treatment.
A decrease in the α 1 -antitrypsin value is given in
- hereditary α 1 -antitrypsin deficiency ,
- Jaundice prolongatus or hepatitis of the newborn ,
- childish chronic hepatitis or liver cirrhosis or
- Emphysema .
Symptoms of AAT deficiency
In the AAT deficiency, proteases lead to the loss of connective and functional tissue in the lungs . This results in a functional disorder similar to chronic obstructive pulmonary disease (COPD) and in particular pulmonary emphysema . This course can lead to death from lung failure. The severity of the disease can be determined technically via computed tomography of the lungs, lung function (especially FEV1 ) and a survey of the blood gases .
The normal concentration of α 1 -antitrypsin in the blood plasma is 83 to 199 mg / dl. In the course of inflammatory processes, the value increases. Compared to the C-reactive protein , the activity measurement of AAT is a better marker for observing the course of an inflammation. If there is a suspicion of a deficiency in AAT, a simultaneous determination of the C-reactive protein is useful, as inflammation can mask the deficiency.
therapy
First of all, a therapy like that for COPD comes into consideration. Furthermore, an intravenous carried substitution with AAT when the disease has not yet progressed too far. Newer therapeutic approaches also suggest inhalation of AAT.
Web links
- Proteopedia: α-1-Antitrypsin (English)
- Jennifer McDowall / Interpro: Protein Of The Month: α-1-Antitrypsin. (English)
- Α-1 antitrypsin. In: Online Mendelian Inheritance in Man . (English)
Individual evidence
- ↑ American Thoracic Society / European Respiratory Society statement: standards for the diagnosis and management of individuals with alpha-1 antitrypsin deficiency. In: American journal of respiratory and critical care medicine. Volume 168, Number 7, October 2003, pp. 818-900, ISSN 1535-4970 . doi : 10.1164 / rccm.168.7.818 . PMID 14522813 .
- ^ R. Siekmeier: Lung deposition of inhaled alpha-1-proteinase inhibitor (alpha 1-PI) - problems and experience of alpha1-PI inhalation therapy in patients with hereditary alpha1-PI deficiency and cystic fibrosis. In: European journal of medical research. Volume 15 Suppl 2, November 2010, pp. 164-174, ISSN 0949-2321 . PMID 21147646 . (Review).
