A1AT

Related Reading

Alpha-1 Antitrypsin is a glycoprotein. It contains 10 to 20 percent sugar and is mainly made by the liver. Molecular weight 5.6kD, in vivo half-life 5.6 days, the most important component of 1-globulin on routine protein electrophoresis. Its biological function lies in the inhibition of trypsin, chymotrypsin, hyaluronidase, plasmin, elastic protease, etc., as well as the inhibition of thrombin, urokinase and other enzymes. It is a broad-spectrum protease inhibitor. It is also an acute reactive protein in inflammatory disorders, α 1. Antitrypsin can enter the interstitial fluid through capillaries, which is often at a high concentration in the local inflammation and has a certain limiting effect on acute inflammatory diseases.

Figure 1.Protein structure of Alpha-1 Antitrypsin.

Functions

A1AT is a 52-KDA serpin, considered to be the most prominent serpin in medicine; The term -1,antitrypsin and protease inhibitor (Pi) are often used interchangeably. Most serines inactivate enzymes by covalently binding to them. These enzymes are locally released at relatively low concentrations and are immediately cleared by proteins such as A1AT. In the acute phase response, further elevations are needed to "limit" the damage caused by activated neutrophils and their elastin enzymes (which destroy connective tissue fibroelasin). In addition to limiting elastin activity to limit tissue degradation, A1PI can also induce lymphocytes to move through the thymus through tissues (including immature T cells), and immature T cells in the thymus mature into immune-capable T cells, which are released into the tissue to improve the immune response. Like all serine protease inhibitors, A1AT has a typical lamellar and helical secondary structure. Mutations in these regions may lead to the aggregation and accumulation of nonfunctional proteins in the liver.

Role in disease

Diseases of this protein include alpha-1 antitrypsin deficiency, which is an autosomal dominant genetic disease, in which alpha-1 antitrypsin deficiency can lead to chronic tissue suppression. This in particular leads to the degeneration of lung tissue and ultimately to the characteristic manifestations of emphysema. [11] There is evidence that cigarette smoke can cause the oxidation of α1-antitrypsin methionine 358 (382 pre-treated form, containing 24 amino acid signal peptide), which is an essential residue for binding elastase. This is considered to be one of the main mechanisms by which smoking (or secondhand smoke) can cause emphysema. Since A1AT is expressed in the liver, certain mutations in the gene encoding this protein can cause folding errors and impaired secretion, leading to liver cirrhosis.

Applications

Alpha-1 antitrypsin concentrate is prepared from blood donor plasma. The U.S. Food and Drug Administration (FDA) has approved the use of four alpha-1 antitrypsin products derived from human plasma: Prolastin, Zemaira, Glassia and Aralast. These products for intravenous enhanced A1AT treatment may cost up to $100,000 per person per year. It is administered intravenously at a dose of 60 mg/kg once a week; although higher doses of the drug can be used to interrupt weekly use, such as vacations, it does not provide additional benefits. In August 2015, the European Union approved Alpha1-protease inhibitor (Respreeza) for medical use. It is indicated as a maintenance treatment to slow the progression of emphysema in adults with severe alpha 1-protease inhibitor deficiency (eg genotype PiZZ, PiZ (ineffective), Pi (ineffective, ineffective), PiSZ). People should receive the best drug and non-drug treatments and show evidence of progressive lung disease, these patients should be evaluated by experienced medical staff.

Reference

1. Lapidot T.; et al. Current understanding of stem cell mobilization: the roles of chemokines, proteolytic enzymes, adhesion molecules, cytokines, and stromal cells. Exp Hematol. 2012,30 (9): 973–981.