Phospholipase a2

Inflammation and Regeneration volume 36Article number: 7 Cite this article. Metrics details.

Federal government websites often end in. The site is secure. The phospholipase A 2 PLA 2 superfamily consists of many different groups of enzymes that catalyze the hydrolysis of the sn-2 ester bond in a variety of different phospholipids. The products of this reaction, a free fatty acid, and lysophospholipid have many different important physiological roles. This review focuses on the superfamily of PLA 2 enzymes, and then uses three specific examples of these enzymes to examine the differing biochemistry of the three main types of these enzymes. PLA 2 s form a superfamily that currently contains fifteen separate, identifiable groups and numerous subgroups of PLA 2 [ 1 — 3 ]. These enzymes are characterized by their ability to specifically hydrolyze the sn-2 ester bond of phospholipid substrate as shown in Fig.

Phospholipase a2

The enzyme phospholipase A 2 EC 3. This particular phospholipase specifically recognizes the sn 2 acyl bond of phospholipids and catalytically hydrolyzes the bond, releasing arachidonic acid and lysophosphatidic acid. Upon downstream modification by cyclooxygenases or lipoxygenases , arachidonic acid is modified into active compounds called eicosanoids. Eicosanoids include prostaglandins and leukotrienes , which are categorized as anti-inflammatory and inflammatory mediators. PLA2 enzymes are commonly found in mammalian tissues as well as arachnid, insect, and snake venom. Due to the increased presence and activity of PLA2 resulting from a snake or insect bite, arachidonic acid is released from the phospholipid membrane disproportionately. As a result, inflammation and pain occur at the site. Additional types of phospholipases include phospholipase A 1 , phospholipase B , phospholipase C , and phospholipase D. Phospholipases A 2 include several unrelated protein families with common enzymatic activity. Two most notable families are secreted and cytosolic phospholipases A 2. The extracellular forms of phospholipases A 2 have been isolated from different venoms snake , [5] bee , and wasp , from virtually every studied mammalian tissue including pancreas and kidney as well as from bacteria. Pancreatic sPLA2 serve for the initial digestion of phospholipid compounds in dietary fat. Venom phospholipases help to immobilize prey by promoting cell lysis [ citation needed ].

Metabolism : lipid metabolism — eicosanoid metabolism enzymes. Structural and functional effects of tryptophans inserted into the membrane-binding and substrate-binding sites of human group IIA phospholipase A2, phospholipase a2.

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Federal government websites often end in. Before sharing sensitive information, make sure you're on a federal government site. The site is secure. NCBI Bookshelf. Jarett Casale ; Salah Eddine O. Kacimi ; Matthew Varacallo. Kacimi 2 ; Matthew Varacallo 3. Phospholipase A PLA comprises a supergroup of esterase enzymes present in all human cells that play a key role in mediating the production of free fatty acids and lysophospholipids from glycerophospholipids.

Phospholipase a2

Federal government websites often end in. The site is secure. The data presented in this review were compiled from the cited work. Details about the adapted figures and graphic are available upon request. The phospholipase A2 PLA2 superfamily of phospholipase enzymes hydrolyzes the ester bond at the sn-2 position of the phospholipids, generating a free fatty acid and a lysophospholipid. The superfamily of PLA2 comprises at least six big families of isoenzymes, based on their structure, location, substrate specificity and physiologic roles.

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Identification of the phosphorylation sites of cytosolic phospholipase A2 in agonist-stimulated human platelets and HeLa cells. Conclusion The PLA 2 superfamily of enzymes mediates a variety of important cellular functions. In addition, the following human proteins contain the phospholipase A 2 domain :. His , Asp, and 2 water molecules are also shown. These unsaturated fatty acids released by sPLA 2 -V dampen the M1 macrophage polarization by saturated fatty acids e. The enzyme contains the six conserved disulfide bonds from 28—44, 26—, 43—99, 50—92, 60—85, and 78—80, as well as the additional disulfide bridge from 11—71 [ 39 ]. Immune balance regulation by sPLA 2 -V. Group X secretory phospholipase A 2 negatively regulates adipogenesis in murine models. Emerging roles of secreted phospholipase A 2 enzymes: lessons from transgenic and knockout mice. Platelet-activating factor and related lipid mediators. Given the increased incidence of metabolic disorders resulting from the genetic ablation of Th2 or M2 inducers e. The first cytosolic PLA 2 was isolated from neutrophils and platetlets in

The enzyme phospholipase A 2 EC 3. This particular phospholipase specifically recognizes the sn 2 acyl bond of phospholipids and catalytically hydrolyzes the bond, releasing arachidonic acid and lysophosphatidic acid.

This arachidonic acid is then metabolized to form several inflammatory and thrombogenic molecules. Download citation. Lambeau G, Gelb MH. Increase in phospholipase A 2 activity is an acute-phase reaction that rises during inflammation, which is also seen to be exponentially higher in low back disc herniations compared to rheumatoid arthritis. Reduced fertility and postischaemic brain injury in mice deficient in cytosolic phospholipase A2. The enzyme is not specific in what fatty acid is being released [ , ]. These results imply a human relevance for the metabolic role of sPLA 2 -V. Download PDF. For the enzyme to be active, it must be sequestered to a phospholipid interface. Mutation of these residues significantly decreases the membrane binding of this enzyme [ 59 , 61 ]. All of the sPLA 2 enzymes except group III [ 14 ] display a characteristic increase in activity when substrate is switched from monomeric to higher ordered lipid aggregates, and this is known as interfacial activation [ 15 ]. Download as PDF Printable version. In children, excess levels of sPLA2 have been associated with inflammation thought to exacerbate asthma [11] and ocular surface inflammation dry eye. PMC Copyright notice. His , Asp, and 2 water molecules are also shown.