Phospholipase A2 enzyme

Six DA, Dennis EA (2000) The expanding superfamily of phospholipase A2 enzymes classification and characterization. Biochim Biophys Acta 1488 1—19... 

Kini RM (1997) Venom phospholipase a2 enzymes. John Wiley Sons, Chichester Kini RM, Evans HJ (1989) A model to explain the pharmacological effects of snake venom phospholipases a2. Toxicon 27 613-35... 

Schiavo G, Papini E, Genna G, Montecucco C (1990) An intact interchain disulfide bond is required for the neurotoxicity of tetanus toxin. Infect Immun 58 4136 11 Scott AB, Magoon EH, McNeer KW, Stager DR (1989) Botulinum treatment of strabismus in children. Trans Am Ophthalmol Soc 87 174-180 discussion 180 1 Scott D (1997) Phospholipase A2 structure and catalytic properties. In Kini R (ed) Venom phospholipase A2 enzymes structure, function and mechanism. John Wiley Sons, Chichester, p 97-128. 

Yang C (1997) Chemical modification and functional sites of phospholipases A2. In Kini R (ed) Venom phospholipase A2 enzymes structure, function and mechanism. Wiley Sons, Chichester, pp 185-204... 

Fig. 2. Ptdlns 4,5-P2-derived second messengers. Ptdlns 4,5-P2 is hydrolysed when a phospholipase C (Ptdlns 4,5-P2 phosphodiesterase) is activated following the binding of specific agonists to their surface receptor proteins. The Ptdlns 4,5-P2 is cleaved to yield diacylglycerol (DG), which is a co-activator of protein kinase C and other enzymes, and Ins( 1,4,5)P, which is capable of releasing Ca2 from intracellular stores. The DG often contains arachidonic acid, which is the source of the prostanoids, which are also capable of controlling diverse cellular functions. The arachidonic acid is cleaved from the parent lipid or from DG by specific phospholipase A2 enzymes.

In the enzymatic degumming process, part of the hydratable phosphatides is enzymatically modified by removing the fatty acid on the C-2 position of the glycerol, using a phospholipase A2 enzyme as biocatalyst. These modified phosphatides facilitate the removal of the remaining NHP. Table 4.10 shows the results of an enzymatic degumming... 

Mukherjee AB, Miele L, Pattabiraman N. Phospholipase A2 enzymes - regulation and physiological-role. Biochem Pharmacol 1994 48 1-10. 

Kudo I, Murakami M. 2002. Phospholipase A2 enzymes. Prostaglandins Other Lipid Mediat 68-69 3-58. 

Phospholipase A2 enzymes are involved in detoxifying phospholipid hydroperoxides, which may... 

Dennis, E. A., 1. Cao et al. 2011. Phospholipase A2 enzymes Physical structure, biological function, disease imphcation, chemical inhibition, and therapeutic intervention. RevinilOy. 6130-6185. 

Murakami M, Taketomi Y, Girard C, Yamamoto K, Lambeau G (2010) Emerging roles of secreted phospholipase A2 enzymes lessons from transgenic and knockout mice. Biochimie 92 561 582... 

Scherer, G.F.E. Arnold, B. (1997). Inhibitors of animal phospholipase A2 enzymes are selective inhibitors of auxin-dependent growth. Implications for auxin-induced signal transduction. Planta, 202,462A69. 

Phospholipase A2. Enzymes with sn-2 specificity isolated form snake and bee venoms. They are very stable, are activated by Ca +-ions and are amongst the smallest enzyme molecules (molecular weight about 14,000). 

Claser KB, Mobilio D, Chang JY, Senko N. Phospholipase A2 enzymes regulation and inhibition. Trends Pharmacol Sci 1993 14 92-98. 

Bennet CF, Chiang MY, Wilson-Lingardo L, Wyatt JR. Sequence specific inhibition of human type II phospholipase A2 enzyme activity by phosphorothioate oligonucleotides. Nucleic Acid Research 1994 22 3202-3209. 

Balsinde J, Barbour SE, Bianco I, Dennis EA. Arachidonic acid mobilization in P3881Di macrophages is controlled by two distinct phospholipase A2 enzymes. Proc Natl Acad Sci USA 1994 91 11060-11064. 

It has been demonstrated in vitro that flavonoids inhibit a number of enzymes (elastase, hyaluronidase, cAMP phosphodiesterase, 5-Iipooxygenase, cyclooxygenase, etc.). Quercetin, rutin, myricetin, kaanpferol and morin inhibit the 5-Iipooxygenase enzyme. Quercetin also inhibits the 12-Upooxygenase and the cyclooxygenase enzymes. Flavones inhibit the phospholipase A2 enzyme and can be used as anti-inflammatory and antiirritant agent. 

Phospholipase A2 enzymes also have other important metabolic functions in addition to the overall destruction of phospholipids as catalysed by digestive pancreatic or venom enzymes. An enzyme in mitochondrial membranes seems to be intimately connected with the energy state of this organelle. Thus, the phospholipase is inactive in fully coupled mitochondria and only becomes active when ATP and respiratory control drop to low levels. Also, the widespread distribution of phospholipases A2 allows many tissues to perform retailoring of the molecular species of membrane lipids by the Lands mechanism. In this process, named after Lands, the American biochemist who first described it, cleavage of the acyl group from the sn-2 position yields a lysophospholipid which can be re-acylated with a new fatty acid from acyl-CoA (Figure 7.8). 

---