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Neutrophil Elastase
Neutrophil elastase (, ''leukocyte elastase'', ''ELANE'', ''ELA2'', ''elastase 2'', ''neutrophil'', ''elaszym'', ''serine elastase'', subtype ''human leukocyte elastase (HLE)'') is a serine proteinase in the same family as chymotrypsin and has broad substrate specificity. Neutrophil elastase is secreted by neutrophils during inflammation, and destroys bacteria and host tissue. It also localizes to neutrophil extracellular traps (NETs), via its high affinity for DNA, an unusual property for serine proteases. As with other serine proteinases it contains a charge relay system composed of the catalytic triad of histidine, aspartate, and serine residues that are dispersed throughout the primary sequence of the polypeptide but that are brought together in the three dimensional conformation of the folded protein. The gene encoding neutrophil elastase, ELA2, consists of five exons. Neutrophil elastase is closely related to other cytotoxic immune serine proteases, such as the granzymes a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proteinase
A protease (also called a peptidase, proteinase, or proteolytic enzyme) is an enzyme that catalyzes proteolysis, breaking down proteins into smaller polypeptides or single amino acids, and spurring the formation of new protein products. They do this by cleaving the peptide bonds within proteins by hydrolysis, a reaction where water breaks bonds. Proteases are involved in numerous biological pathways, including digestion of ingested proteins, protein catabolism (breakdown of old proteins), and cell signaling. In the absence of functional accelerants, proteolysis would be very slow, taking hundreds of years. Proteases can be found in all forms of life and viruses. They have independently evolved multiple times, and different classes of protease can perform the same reaction by completely different catalytic mechanisms. Classification Based on catalytic residue Proteases can be classified into seven broad groups: * Serine proteases - using a serine alcohol * Cysteine prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbohydrate
A carbohydrate () is a biomolecule composed of carbon (C), hydrogen (H), and oxygen (O) atoms. The typical hydrogen-to-oxygen atomic ratio is 2:1, analogous to that of water, and is represented by the empirical formula (where ''m'' and ''n'' may differ). This formula does not imply direct covalent bonding between hydrogen and oxygen atoms; for example, in , hydrogen is covalently bonded to carbon, not oxygen. While the 2:1 hydrogen-to-oxygen ratio is characteristic of many carbohydrates, exceptions exist. For instance, uronic acids and deoxy-sugars like fucose deviate from this precise stoichiometric definition. Conversely, some compounds conforming to this definition, such as formaldehyde and acetic acid, are not classified as carbohydrates. The term is predominantly used in biochemistry, functioning as a synonym for saccharide (), a group that includes sugars, starch, and cellulose. The saccharides are divided into four chemical groups: monosaccharides, disaccharides, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elastase
In molecular biology, elastase is an enzyme from the class of proteases (peptidases) that break down proteins, specifically one that can break down elastin. In other words, the name only refers to the substrate specificity (i.e. what proteins it can digest), not to any kind of evolutionary grouping. Forms and classification Eight human genes exist for elastase: The four "pancreatic elastases", chymotrypsin, and neutrophil elastase are serine proteases. The "macrophage elastase" is a matrix metallopeptidase. Chymotrypsin is weaker at digesting elastin than the architypical pancreatic elastase. Some bacteria (including ''Pseudomonas aeruginosa'') also produce elastase; bacterial elestases work in many ways and include serine proteases, aspartic proteases, thiol proteases, and metalloenzymes. Function The fact that elastase can break down elastin in test tubes (while other proteases cannot) does not imply that there is a unifying function for all elastases in the living ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha 2-antiplasmin
Alpha 2-antiplasmin (or α2-antiplasmin or plasmin inhibitor) 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. Structure Alpha 2-antiplasmin (α2AP) is a member of the serine protease inhibitor (serpin) superfamily and is structurally characterized by a central serpin domain flanked by unique N-terminal, N- and C-terminal extensions. The mature human α2AP protein consists of 452 amino acids, with a 12-residue N-terminus, a central serpin domain, and a C-terminal tail of approximately 55 residues. The reactive center loop, which is crucial for its inhibitory function, protrudes from the central serpin domain and contains the Arg364-Met365 peptide bond that is specifically targeted and cleaved by plasmin. There are two main circulating form ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpin
Serpins are a superfamily of proteins with similar structures that were first identified for their protease inhibition activity and are found in all kingdoms of life. The acronym serpin was originally coined because the first serpins to be identified act on chymotrypsin-like serine proteases (serine protease inhibitors). They are notable for their unusual mechanism of action, in which they irreversibly inhibit their target protease by undergoing a large conformational change to disrupt the target's active site. This contrasts with the more common competitive mechanism for protease inhibitors that bind to and block access to the protease active site. Protease inhibition by serpins controls an array of biological processes, including coagulation and inflammation, and consequently these proteins are the target of medical research. Their unique conformational change also makes them of interest to the structural biology and protein folding research communities. The conformationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neutropenia
Neutropenia is an abnormally low concentration of neutrophils (a type of white blood cell) in the blood. Neutrophils make up the majority of circulating white blood cells and serve as the primary defense against infections by destroying bacteria, bacterial fragments and immunoglobulin-bound viruses in the blood. People with neutropenia are more susceptible to bacterial infections and, without prompt medical attention, the condition may become life-threatening (neutropenic sepsis). Neutropenia can be divided into congenital and acquired, with severe congenital neutropenia (SCN) and cyclic neutropenia (CyN) being autosomal dominant and mostly caused by heterozygous mutations in the ELANE gene ( neutrophil elastase). Neutropenia can be acute (temporary) or chronic (long lasting). The term is sometimes used interchangeably with "leukopenia" ("deficit in the number of white blood cells"). Decreased production of neutrophils is associated with deficiencies of vitamin B12 and fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emphysema
Emphysema is any air-filled enlargement in the body's tissues. Most commonly emphysema refers to the permanent enlargement of air spaces (alveoli) in the lungs, and is also known as pulmonary emphysema. Emphysema is a lower respiratory tract disease, characterised by enlarged air-filled spaces in the lungs, that can vary in size and may be very large. The spaces are caused by the breakdown of the Alveolar wall, walls of the Pulmonary alveolus, alveoli, which replace the spongy Parenchyma#Lungs, lung tissue. This reduces the total alveolar surface available for gas exchange leading to a reduction in oxygen supply for the blood. Emphysema usually affects the middle aged or Old age, older population because it takes time to develop with the effects of tobacco smoking and other risk factors. Alpha-1 antitrypsin deficiency is a genetic risk factor that may lead to the condition presenting earlier. When associated with significant airflow limitation, emphysema is a Chronic obstructive ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Severe Congenital Neutropenia
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. Most cases of SCN respond to treatment with granulocyte colony-stimulating factor ( filgrastim), which increases the neutrophil count and decreases the severity and frequency of infections. Although this treatment has significantly improved survival, people with SCN are at risk of long-term complications such as hematopoietic clonal disorders (myelodysplastic syndrome, acute myeloid leukemia). Kostmann disease (SCN3), the initial subtype recognized, was clinically d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Neutropenia
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. Signs and symptoms The common symptoms of neutropenia are recurrent fever, malaise, inflammation of the tissues surrounding the teeth, mouth ulcers, inflammation and bacterial infection of the respiratory tract, digestive tract, skin, and abdominal pain. It is considered th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Azurophil Granules
An azurophilic granule is a cellular object readily stainable with a Romanowsky stain. In white blood cells and hyperchromatin, staining imparts a burgundy or merlot coloration. Neutrophils in particular are known for containing azurophils loaded with a wide variety of anti-microbial defensins that fuse with phagocytic vacuoles. Azurophils may contain myeloperoxidase, phospholipase A2, acid hydrolases, elastase, defensins, neutral serine proteases, bactericidal permeability-increasing protein, lysozyme, cathepsin G, proteinase 3, and proteoglycans. Azurophil granules are also known as "primary granules". Furthermore, the term "azurophils" may refer to a unique type of cells, identified only in reptiles. These cells are similar in size to so-called heterophils with abundant cytoplasm that is finely to coarsely granular and may sometimes contain vacuoles. Granules may impart a purplish hue to the cytoplasm, particularly to the outer region. Occasionally, azurophils are o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and non-coding genes. During gene expression (the synthesis of Gene product, RNA or protein from a gene), DNA is first transcription (biology), copied into RNA. RNA can be non-coding RNA, directly functional or be the intermediate protein biosynthesis, template for the synthesis of a protein. The transmission of genes to an organism's offspring, is the basis of the inheritance of phenotypic traits from one generation to the next. These genes make up different DNA sequences, together called a genotype, that is specific to every given individual, within the gene pool of the population (biology), population of a given species. The genotype, along with environmental and developmental factors, ultimately determines the phenotype ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
