Uses
Cell permeable, amphiphilic, mast cell degranulating tetradecapeptide. Stimulates glycogenolysis and phospholipase D2 (PLD2) activity. Alters G-proteins in brain membranes. Directly activates G proteins by a mechanism analogous to that of G protein-coupled receptors. Acts preferentially on Gi and Go rather than Gs. Stimulates exocytosis and phosphoinositide breakdown in a variety of cells. Inhibits calmodulin, and activates PLA2. Acts as a mitogen in Swiss 3T3 cells and stimulates pertussis toxin-sensitive arachidonate release without phosphoinositide breakdown.
Definition
ChEBI: A member of the class of mastopyrans that is a 14-amino acid polypeptide comprising isoleucyl, asparaginyl, leucyl, lysyl, alanyl, leucyl, alanyl, alanyl, leucyl, alanyl, lysyl, lysyl, isoleucyl, and leucinamide residues coupled in sequence. It is the majo
active component of the venom of the vespid wasp, Vespula lewisii and causes degranulation of mast cells.
Biochem/physiol Actions
Mastoparan effectively stimulates exocytosis from diverse mammalian cells. The encoded protein facilitates the secretion of histamine from mast cells, serotonin from platelets, catecholamines from chromaffin cells and prolactin from the anterior pituitary. In addition, it is also involved in activation of Phospholipase A2 and phosphoinositides (Pl) break down. Mastoparan functions as an inhibitor for calmodulin-stimulated phosphodiesterase. Mastoparan helps in mitochondrial permeability transition by enhancing an apparent bimodal mechanism of action.
