Membrane structure, toxins and phospholipase A2 activity.
The phospholipid-hydrolyzing enzyme phospholipase A2 (PLA2) (EC 3.1.1.4) exists in several forms which can be located in the cytosol or on cellular membranes. We review briefly cellular regulatory mechanisms involving covalent modification by protein kinase C and the action of Ca2+, cytokines, G proteins and other cellular proteins. The major focus is the role of phospholipid structure on PLA2 activity, including (1) the mechanism of PLA2 action on synthetic phospholipid bilayers, (2) perturbation of synthetic and cellular membranes with lipophilic agents and membrane-interactive peptides and (3) the ability of these agents to activate endogenous PLA2 activity, with emphasis on the venom and plant toxins melittin, cardiotoxin and Pyrularia thionein.
Vernon
L P
LP
Department of Chemistry, Brigham Young University, Provo, UT 84602.
Bell
J D
JD
D000818:Animals; D002118:Calcium / Q000502:physiology; D002462:Cell Membrane / Q000378:metabolism / Q000502:physiology; D016207:Cytokines / Q000494:pharmacology; D004789:Enzyme Activation / Q000187:drug effects; D019204:GTP-Binding Proteins / Q000502:physiology; D006801:Humans; D008954:Models, Biological; D010741:Phospholipases A / Q000378:metabolism* / Q000502:physiology; D054467:Phospholipases A2; D014118:Toxins, Biological / Q000494:pharmacology
D016207:Cytokines; D014118:Toxins, Biological; D010741:Phospholipases A; D054467:Phospholipases A2; D019204:GTP-Binding Proteins; D002118:Calcium