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Paraoxonase
Paraoxonases are a family of mammalian enzymes with aryldialkylphosphatase activity. There are three paraoxonase isozymes, which were originally discovered for their involvement in the hydrolysis of organophosphates. Research has indicated the enzymatic activity of paraoxonases is more diversified than its activity as an organophosphatase. Esterase and lactonase activity has also been observed from these enzymes and though the physiologically relevant substrates for these enzymes are unknown, it is likely that lactones are the main substrate (although there is a relatively high level of variation in substrate specificity among these enzymes). Most of the studies on the paraoxonase family have specifically looked at the paraoxonase 1 type, leaving much to be learned about the remaining two. The study of this enzyme family has many potential consequences in preventative medicine and toxicology as well as in certain societal contexts. The genes that encode for these enzymes have a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PON1
Serum paraoxonase and arylesterase 1 (PON1) also known as A esterase , homocysteine thiolactonase or serum aryldialkylphosphatase 1 is an enzyme that in humans is encoded by the ''PON1'' gene. Paraoxonase 1 has esterase and more specifically paraoxonase activity. ''PON1'' is the first discovered member of a multigene family also containing ''PON2'' and ''PON3'', the genes for which are located adjacent to each other on chromosome 7. Structure Human PON1 is a glycoprotein composed of 354 amino acids and has a molecular weight of 43000 Daltons which associates with high-density lipoprotein (HDL, cholesterol) in the circulation. Serum PON1 is secreted mainly by the liver, although local synthesis occurs in several tissues and PON1 protein is found in almost all tissues. X-ray crystallography has revealed the structure of PON1 to be a 6 bladed propeller with a unique lid structure covering the active site passage which allows association with HDL. Function PON1 is responsible fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PON2
Serum paraoxonase/arylesterase 2 is an enzyme that in humans is encoded by the ''PON2'' gene. This gene encodes a member of the paraoxonase gene family, which includes three known members located adjacent to each other on the long arm of chromosome 7 Chromosome 7 is one of the 23 pairs of chromosomes in humans, who normally have two copies of this chromosome. Chromosome 7 spans about 159 million base pairs (the building material of DNA) and represents between 5 and 5.5 percent of the total DN .... The encoded protein is ubiquitously expressed in human tissues, membrane-bound, and may act as a cellular antioxidant, protecting cells from oxidative stress. Hydrolytic activity against acylhomoserine lactones, important bacterial quorum-sensing mediators, suggests the encoded protein may also play a role in defense responses to pathogenic bacteria. Mutations in this gene may be associated with vascular disease and a number of quantitative phenotypes related to diabetes. Alternatively ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PON3
Paraoxonase 3, also known as PON3, is a protein which in humans is encoded by the ''PON3'' gene. Function This gene is a member of the paraoxonase family and lies in a cluster on chromosome 7 with the other two family members. The encoded protein is secreted into the bloodstream and associates with high-density lipoprotein ( HDL). The protein also rapidly hydrolyzes lactones and can inhibit the oxidation of low-density lipoprotein (LDL), a function that is believed to slow the initiation and progression of atherosclerosis Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheroma, atheromatous plaque. At onset there are usu .... Alternatively spliced variants which encode different protein isoforms have been described; however, only one has been fully characterized. References Further reading * * * * * * * * * * * * * * * * * * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lactonase
Lactonase (EC 3.1.1.81, acyl-homoserine lactonase; systematic name ''N''-acyl-L-homoserine-lactone lactonohydrolase) is a metalloenzyme, produced by certain species of bacteria, which targets and inactivates acylated homoserine lactones (AHLs). It catalyzes the reaction : an ''N''-acyl-L-homoserine lactone + H2O \rightleftharpoons an ''N''-acyl-L-homoserine Many species of α-, β-, and γ-proteobacteria produce acylated homoserine lactones, small hormone-like molecules commonly used as communication signals between bacterial cells in a population to regulate certain gene expression and phenotypic behaviours. This type of gene regulation is known as quorum sensing. Other names for these types of enzymes are Quorum-quenching ''N''-acyl-homoserine lactonase, acyl homoserine degrading enzyme, acyl-homoserine lactone acylase, AHL lactonase, AHL-degrading enzyme, AHL-inactivating enzyme, AHLase, AhlD, AhlK, AiiA, AiiA lactonase, AiiA-like protein, AiiB, AiiC, AttM, delactonase, lac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antioxidant
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. This can lead to polymerization and other chain reactions. They are frequently added to industrial products, such as fuels and lubricants, to prevent oxidation, and to foods to prevent spoilage, in particular the rancidification of oils and fats. In cells, antioxidants such as glutathione, mycothiol or bacillithiol, and enzyme systems like superoxide dismutase, can prevent damage from oxidative stress. The only dietary antioxidants are vitamins A, C, and E, but the term ''antioxidant'' has also been applied to numerous other dietary compounds that only have antioxidant properties in vitro, with little evidence for antioxidant properties in vivo. Dietary supplements marketed as antioxidants have not been shown to maintain health or prevent disease in humans. History As part of their adaptation from marine life, terrestrial plants began producing non-marine antioxi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atherogenic
Atherosclerosis is a pattern of the disease arteriosclerosis in which the wall of the artery develops abnormalities, called lesions. These lesions may lead to narrowing due to the buildup of atheromatous plaque. At onset there are usually no symptoms, but if they develop, symptoms generally begin around middle age. When severe, it can result in coronary artery disease, stroke, peripheral artery disease, or kidney problems, depending on which arteries are affected. The exact cause is not known and is proposed to be multifactorial. Risk factors include abnormal cholesterol levels, elevated levels of inflammatory markers, high blood pressure, diabetes, smoking, obesity, family history, genetic, and an unhealthy diet. Plaque is made up of fat, cholesterol, calcium, and other substances found in the blood. The narrowing of arteries limits the flow of oxygen-rich blood to parts of the body. Diagnosis is based upon a physical exam, electrocardiogram, and exercise stress test, among ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arylesterase
The enzyme arylesterase (EC 3.1.1.2) catalyzes the reaction :a phenyl acetate + H2O \rightleftharpoons a phenol + acetate This enzyme belongs to the family of hydrolases, specifically those acting on carboxylic ester bonds. The systematic name of this enzyme class is aryl-ester hydrolase. Other names in common use include A-esterase, paraoxonase, and aromatic esterase. This enzyme participates in bisphenol a degradation. Structural studies As of late 2007, two structures A structure is an arrangement and organization of interrelated elements in a material object or system, or the object or system so organized. Material structures include man-made objects such as buildings and machines and natural objects such as ... have been solved for this class of enzymes, with PDB accession codes and . References * * * * * * * * EC 3.1.1 Enzymes of known structure {{3.1-enzyme-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serum Paraoxonase-1 Active Site With Residue Labels
{{disambiguation, surname ...
Serum may refer to: *Serum (blood), plasma from which the clotting proteins have been removed **Antiserum, blood serum with specific antibodies for passive immunity *Serous fluid, any clear bodily fluid *Truth serum, a drug that is likely to make people tell the truth *Gary Serum (born 1956), American baseball player *Serum, a software synthesizer VST created by Steve Duda See also *Sera (other) Sera may refer to: People * Ryu Sera (born 1987), South Korean singer * Sera Cahoone (born 1975), Seattle-based singer and musician Places * Sera, Hiroshima, a town in Japan * Sera District, Hiroshima * Sera Monastery, Lhasa, Tibet Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrolysis
Hydrolysis (; ) is any chemical reaction in which a molecule of water breaks one or more chemical bonds. The term is used broadly for substitution reaction, substitution, elimination reaction, elimination, and solvation reactions in which water is the nucleophile. Biological hydrolysis is the cleavage of biomolecules where a water molecule is consumed to effect the separation of a larger molecule into component parts. When a carbohydrate is broken into its component sugar molecules by hydrolysis (e.g., sucrose being broken down into glucose and fructose), this is recognized as saccharification. Hydrolysis reactions can be the reverse of a condensation reaction in which two molecules join into a larger one and eject a water molecule. Thus hydrolysis adds water to break down, whereas condensation builds up by removing water. Types Usually hydrolysis is a chemical process in which a molecule of water is added to a substance. Sometimes this addition causes both the substance and w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serum Paraoxonase-1 PyMol Video
{{disambiguation, surname ...
Serum may refer to: *Serum (blood), plasma from which the clotting proteins have been removed **Antiserum, blood serum with specific antibodies for passive immunity *Serous fluid, any clear bodily fluid *Truth serum, a drug that is likely to make people tell the truth *Gary Serum (born 1956), American baseball player *Serum, a software synthesizer VST created by Steve Duda See also *Sera (other) Sera may refer to: People * Ryu Sera (born 1987), South Korean singer * Sera Cahoone (born 1975), Seattle-based singer and musician Places * Sera, Hiroshima, a town in Japan * Sera District, Hiroshima * Sera Monastery, Lhasa, Tibet Me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anion
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons while an anion is a negatively charged ion with more electrons than protons. Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed atomic or monatomic ions, while two or more atoms form molecular ions or polyatomic ions. In the case of physical ionization in a fluid (gas or liquid), "ion pairs" are created by spontaneous molecule collisions, where each generated pair consists of a free electron and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and Functio laesa, loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immune system, innate immunity, as compared to adaptive immune system, adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
