Phospholipase
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A phospholipase is an enzyme that converts phospholipids into fatty acids and other lipophilic substances. There are four major classes, termed A, B, C and D.
Phospholipase A (PLA)
Phospholipase A2 catalyses the first step in the formation of arachidonic acid, the precursor of eicosanoids (leukotrienes, prostaglandins). Some eicosanoids are synthesized from diacylglycerol, released from the lipid bilayer by the phospholipase C (see below).The PDB code for phospolipase A2 is 1CJY (http://www.rcsb.org/pdb/cgi/explore.cgi?pid=258171034362047&page=20&pdbId=1CJY); the EC code is EC 3.1.1.4.
Phospholipase B (PLB)
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Phospholipase C (PLC)
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(Bacillus Cereus: PDB 1AH7 (http://www.rcsb.org/pdb/cgi/explore.cgi?pid=266091034362355&page=0&pdbId=1AH7), EC 3.1.4.3) Phospholipase C is a key enzyme in phosphatidylinositol (PIP2) metabolism. It is activated by either Gαs protein (making it part of a G protein-coupled receptor signal transduction pathway) or by transmembrane receptors with intrinsic or associated tyrosine kinase activity.
It converts phosphatidylinositol to inositol triphosphate (IP3) and diacylglycerol (DAG). These can act on other proteins in cells to increase activity of enzymes, e.g. protein kinase C, or on membrane channels such as calcium in the sarcoplasmic reticulum in smooth muscle.de:Phospholipase C es:Fosfolipasa