Phospholipase properties

Pseudopterosin A is a member of a group of marine natural products which show potent antiinflammatory properties, but which are not prostaglandin biosynthesis inhibitors. Structurally similar to phosphatidyl inositol, they may function as phospholipase inhibitors, and, as such, may be the forerunners of a new class of therapeutic agents. 

Pyridyl functionalized tris(pyrazolyl)borate ligands show some interesting properties including the formation of polynuclear zinc complexes.23,1 Some of these contain extensive H bonding and have potential as models for multinuclear zinc enzymes such as phospholipase C or PI nuclease.235 A bis-ligand complex of the hydrotris(5-methyl-3-(3-pyridyl)pyrazolyl)borate ligand (23) shows octahedral coordination of all six pyrazole nitrogen donors despite the steric bulk. 

Esterases play a role in regulating the platelet-activating factor (PAF), a lipid with hypotensive properties [96], Phospholipase A2 (EC 3.1.1.4) is involved in this pathway by hydrolyzing a precursor to lyso-PAF and a free fatty acid. The activity of PAF, formed by acetylation of lyso-PAF, is controlled by an esterase hydrolyzing the acetate moiety [100]. 

Selected entries from Methods in Enzymology [vol, page(s)] Phosphatidylinositol-specific phospholipases C from Bacillus ce-reus and Bacillus thuringiensis, 197, 493 assays for phosphoinosi-tide-specific phospholipase C and purification of isozymes from bovine brain, 197, 502 properties of phospholipase C isozymes, 197, 511 phosphatidylinositol-specific phospholipase C from human platelets, 197, 518 purification of guinea pig uterus phos-phoinositide-specific phospholipase C, 197, 526. 

Natural fats and oils can be used directly in products, either individually or as mixtures. In many cases, however, it is necessary to modify their properties, particularly their melting characteristics, to make them suitable for particular applications. Therefore, the oils and fats industry has developed several modification processes using enzyme technology. In particular, lipases (and lately cutinases), phospholipases and pectinases can be used for interesterification processes, ester syntheses and in olive-oil extraction. 

Snoke and Nordlie (82, 83) have extended these studies of Duttera et al. (87) to include PPS-glucose phosphotransferase as well as glucose-6-P phosphohydrolase activity of the enzyme and have also noted essentially parallel progressive losses of both activities concomitant with release of acid-soluble phosphate resulting from phospholipase C action. A partial (fed animals) or total (fasted rats) restoration of both activities was effected by phospholipid supplementation of phospholipase-treated preparations. However, as indicated by detailed studies of catalytic properties of the various preparations, the enzyme was not restored to its... 

Chabot C., Gagne J., Giguere C., Bernard J., Baudry M., and Massicotte G. (1998). Bidirectional modulation of AMPA receptor properties by exogenous phospholipase A2 in the hippocampus. Hippocampus 8 299-309. 

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