Alpha-1 antitrypsin or α1-antitrypsin is a protein belonging to the serpin superfamily. It is encoded in humans by the SERPINA1 gene. A protease inhibitor, it is also known as alpha1–proteinase inhibitor (A1PI) or alpha1-antiproteinase (A1AP) because it inhibits various proteases. In older biomedical literature it was sometimes called serum trypsin inhibitor, because its capability as a trypsin inhibitor was a salient feature of its early study. As a type of enzyme inhibitor, it protects tissues from enzymes of inflammatory cells, especially neutrophil elastase, and has a reference range in blood of 0.9–2.3 g/L, but the concentration can rise manyfold upon acute inflammation.
In molecular biology, elastase is an enzyme from the class of proteases (peptidases) that break down proteins. In particular, it is a serine protease.
Alpha 2-antiplasmin is a serine protease inhibitor (serpin) responsible for inactivating plasmin. Plasmin is an important enzyme that participates in fibrinolysis and degradation of various other proteins. This protein is encoded by the SERPINF2 gene.
Cyclic neutropenia (CyN) is a rare hematologic disorder and form of congenital neutropenia that tends to occur approximately every three weeks and lasting for few days at a time due to changing rates of neutrophil production by the bone marrow. It causes a temporary condition with a low absolute neutrophil count and because the neutrophils make up the majority of circulating white blood cells it places the body at severe risk of inflammation and infection. In comparison to severe congenital neutropenia, it responds well to treatment with granulocyte colony-stimulating factor (filgrastim), which increases the neutrophil count, shortens the cycle length, as well decreases the severity and frequency of infections.
Severe congenital neutropenia (SCN), also often known as Kostmann syndrome or disease, is a group of rare disorders that affect myelopoiesis, causing a congenital form of neutropenia, usually without other physical malformations. SCN manifests in infancy with life-threatening bacterial infections. It causes severe pyogenic infections. It can be caused by autosomal dominant inheritance of the ELANE gene, autosomal recessive inheritance of the HAX1 gene. There is an increased risk of leukemia and myelodysplastic cancers.
Proteinase 3, also known as PRTN3, is an enzyme that in humans is encoded by the PRTN3 gene.
Granzyme A is a tryptase and is one of the five granzymes encoded in the human genome. In humans, GzmA is encoded by the GZMA gene in proximity to the GZMK gene on chromosome 5. This enzyme is present in cytotoxic T lymphocyte (CTL) granules.
Heparin cofactor II (HCII), a protein encoded by the SERPIND1 gene, is a coagulation factor that inhibits IIa, and is a cofactor for heparin and dermatan sulfate.
Alpha 1-antichymotrypsin is an alpha globulin glycoprotein that is a member of the serpin superfamily. In humans, it is encoded by the SERPINA3 gene.
Cathepsin G is a protein that in humans is encoded by the CTSG gene. It is one of the three serine proteases of the chymotrypsin family that are stored in the azurophil granules, and also a member of the peptidase S1 protein family. Cathepsin G plays an important role in eliminating intracellular pathogens and breaking down tissues at inflammatory sites, as well as in anti-inflammatory response.
Trypsin-1, also known as cationic trypsinogen, is a protein that in humans is encoded by the PRSS1 gene. Trypsin-1 is the main isoform of trypsinogen secreted by pancreas, the others are trypsin-2, and trypsin-3 (meso-trypsinogen).
Cathepsin L1 is a protein that in humans is encoded by the CTSL1 gene. The protein is a cysteine cathepsin, a lysosomal cysteine protease that plays a major role in intracellular protein catabolism.
Granulin is a protein that in humans is encoded by the GRN gene. Each granulin protein is cleaved from the precursor progranulin, a 593 amino-acid-long and 68.5 kDa protein. While the function of progranulin and granulin have yet to be determined, both forms of the protein have been implicated in development, inflammation, cell proliferation and protein homeostasis. The 2006 discovery of the GRN mutation in a population of patients with frontotemporal dementia has spurred much research in uncovering the function and involvement in disease of progranulin in the body. While there is a growing body of research on progranulin's role in the body, studies on specific granulin residues are still limited.
Antileukoproteinase, also known as secretory leukocyte protease inhibitor (SLPI), is an enzyme that in humans is encoded by the SLPI gene. SLPI is a highly cationic single-chain protein with eight intramolecular disulfide bonds. It is found in large quantities in bronchial, cervical, and nasal mucosa, saliva, and seminal fluids. SLPI inhibits human leukocyte elastase, human cathepsin G, human trypsin, neutrophil elastase, and mast cell chymase. X-ray crystallography has shown that SLPI has two homologous domains of 53 and 54 amino acids, one of which exhibits anti-protease activity. The other domain is not known to have any function.
Elafin, also known as peptidase inhibitor 3 or skin-derived antileukoprotease (SKALP), is a protein that in humans is encoded by the PI3 gene.
Azurocidin also known as cationic antimicrobial protein CAP37 or heparin-binding protein (HBP) is a protein that in humans is encoded by the AZU1 gene.
Lympho-epithelial Kazal-type-related inhibitor (LEKTI) also known as serine protease inhibitor Kazal-type 5 (SPINK5) is a protein that in humans is encoded by the SPINK5 gene.
Leukocyte elastase inhibitor (LEI) also known as serpin B1 is a protein that in humans is encoded by the SERPINB1 gene. It is a member of the clade B serpins or ov-serpins founded by ovalbumin.
Serine protease inhibitor Kazal-type 2 also known as acrosin-trypsin inhibitor is a protein that in humans is encoded by the SPINK2 gene.
Serine protease 57 is a protein that in humans is encoded by the PRSS57 gene.
