The entomopathogenic bacterium, Xenorhabdus nematophila, induces immunodepression in target insects and finally leads to lethal septicemia of the infected hosts. A hypothesis has been raised that the bacteria inhibit eicosanoid-biosynthesis pathway to interrupt immune signaling of the infected hosts. Here, we show direct evidence that X. nematophila inhibits the activity of phospholipase A2 (PL...

Angiotensin II in proximal tubule epithelium is known to stimulate the release of arachidonic acid after stimulation of phospholipase A2 (PLA2) independent of phospholipase C-mediated signaling. Furthermore, an angiotensin II type 2 receptor subtype has been linked to this signaling cascade. We investigated the regulation and differential stimulation of PLA2s by comparing the PLA2 activities as...

Tremendous advances in understanding the structure and function of the superfamily of phospholipase A2 (PLA2) enzymes has occurred in the twenty-first century. The superfamily includes 15 groups comprising four main types including the secreted sPLA2, cytosolic cPLA2, calcium-independent iPLA2, and platelet activating factor (PAF) acetyl hydrolase/oxidized lipid lipoprotein associated (Lp)PLA2....

Phospholipase A2 (PLA2) treatment has been shown previously to stimulate the sodium-dependent high-affinity choline uptake system as assessed by both the specific binding of [3H]hemicholinium-3 ([ 3H]HCh-3) and the uptake of [3H]choline. In the present study, the specificity of PLA2-induced stimulation upon [3H]HCh-3 binding has been examined. PLA2, as well as phospholipase C (PLC), treatment o...

To elucidate the anti-venom mechanism of persimmon tannin, the interaction between a polymeric persimmon proanthocyanidin fraction (PT40) and phospholipase A2 (PLA2) or bovine serum albumin (BSA) were studied using a competitive binding assay and spectroscopic methods including Fourier transform infrared spectroscopy (FT-IR), circular dichroism (CD), and resonance light scattering (RLS) spectro...

We have recently demonstrated the presence of phospholipase A2 (PLA2) activity in cells from bovine retinal pigment epithelium (RPE) [Jacob et al. (1996) J. Biol. Chem. 271, 19209-19218]. We report here our results on the characterization of this RPE-PLA2 activity. We show that RPE probably contains two types of PLA2 enzyme, as indicated by the results obtained with different PLA2-active fracti...

Human group IB phospholipase A2 (IB-PLA2) and its zymogen (proIB-PLA2) were purified from E.coli. Refolding was carried out by diluting the denatured forms of both IB-PLA2 and proIB-PLA2 with renaturation buffer in which the disulfide bonds were completely reduced. The refolding yield of proIB-PLA2 was increased by about 50% over that of the mature enzyme. The refolding of IB-PLA2 usually produ...

Coix lacryma-jobi, commonly known as job's tear, is a tall grain-bearing tropical plant of the family Poaceae. The ethanolic root extract (ERE) of the plant was investigated for the first time for anti-venom activity against Indian cobra Naja naja venom. In-vitro studies were conducted to determine neutralization of phospholipase A2 (PLA2) activity of the Naja naja venom by the ERE. ERE showed ...

Lipoprotein-associated phospholipase A2 (Lp-PLA2) is produced by inflammatory cells, bound to LDL and other lipoproteins, and hydrolyzes oxidized phospholipids in LDL. Type 2 diabetes is the most common form of diabetes some investigations show the association of lipoprotein-associated phospholipase A2 mass and activity with the incidence of cardiovascular disease (CVD) in populations with high...

Ceramide is a novel second messenger generated by hydrolysis of membrane sphingomyelin by a neutral sphingomyelinase (nSMase). Cytokines such as tumor necrosis factor-α (TNF-α) have been shown to increase intracellular ceramide through phospholipase A2(PLA2)-dependent activation of nSMase. TNF-α has been shown to cause endothelium-independent relaxation in isolated blood vessels. We have previo...