The effects of membrane sterol level on the susceptibility of LM cell plasma membranes to exogenous phospholipases A2 has been investigated. Isolated plasma membranes, containing normal or decreased sterol content, were prepared from mutant LM cell sterol auxotrophs. beta-Bungarotoxin-catalyzed hydrolysis of both endogenous phospholipids and phospholipids introduced into the membranes with beef...

Rabbit antisera elicited against pure pig, horse, ox, and sheep pancreatic phospholipase A2 revealed considerable immunological differences when tested by double immunodiffusion and microcomplement fixation assays. Snake venom phospholipases did not show any detectable cross-reactions with the pancreatic enzymes. Microcomplement fixation also clearly demonstrated conformational differences betw...

Bothrops punctatus is an endangered, semi-arboreal pitviper species distributed in Panamá, Colombia, and Ecuador, whose venom is poorly characterized. In the present work, the protein composition of this venom was profiled using the 'snake venomics' analytical strategy. Decomplexation of the crude venom by RP-HPLC and SDS-PAGE, followed by tandem mass spectrometry of tryptic digests, showed tha...

Endogenous activities of phospholipases A and C in Ureaplasma urealyticum were assayed in cellular fractions of exponential-phase cells. Enzymatic studies indicated that ATPase activity was localized in the plasma membrane fraction and NADH and NADPH dehydrogenase activities were localized in the cytosol fraction. Studies with purified ureaplasma membranes demonstrated that, of three serovars t...

Anandamide (an endocannabinoid) and other bioactive long-chain NAEs (N-acylethanolamines) are formed by direct release from N-acyl-PE (N-acyl-phosphatidylethanolamine) by a PLD (phospholipase D). However, the possible presence of a two-step pathway from N-acyl-PE has also been suggested previously, which comprises (1) the hydrolysis of N-acyl-PE to N-acyl-lysoPE by PLA1/PLA2 enzyme(s) and (2) t...

Increased concentrations of eicosanoids are found in synovial fluids (SF) from patients with rheumatoid arthritis (RA). SF polymorphonuclear leukocytes (PMN), which derive from peripheral blood, usually account for approximately 90% of the cells in RA SF. Since eicosanoid precursor fatty acids (FA) are liberated by phospholipases from membrane phospholipids, we examined phospholipase A2 and C a...