The activity of phospholipase C in crude enzymatic preparation of Melia azadiracht seeds (Neem seeds) was studied by the use of lecithin as a substrate in aqueous medium. The enzyme activity was found optimum at pH 2.5 and temperature 35?C. The phospholipase C was found heat labile, being inactivated 88% within 10 minutes at 90°C

Phosphatidylinositol (PI), an important constituent of membranes, contains stearic acid as the major fatty acid at the sn-1 position. This fatty acid is thought to be incorporated into PI through fatty acid remodeling by sequential deacylation and reacylation. However, the genes responsible for the reaction are unknown, and consequently, the physiological significance of the sn-1 fatty acid rem...

Here we have characterized the Rickettsia prowazekii RP534 protein, a homologue of the Pseudomonas aeruginosa ExoU phospholipase A (PLA) secreted cytotoxin. Our studies showed that purified recombinant RP534 PLA possessed the predicted PLA(2) and lyso-PLA(2) activities based on what has been published for P. aeruginosa ExoU. RP534 also displayed PLA(1) activity under the conditions tested, wher...

Pretreatment with dexamethasone (Dex) was not toxic for U937 cells but caused a rapid lethal response upon subsequent exposure to otherwise nontoxic concentrations of peroxynitrite. This effect was not associated with enhanced formation of hydrogen peroxide taking place after peroxynitrite and was shown previously to play a pivotal role in the ensuing lethal response. Further analyses revealed ...

Vibrio cholerae, responsible for acute gastroenteritis secretes a large multifunctional-autoprocessing repeat-in-toxin (MARTX) toxin linked to evasion of host immune system, facilitating colonization of small intestine. Unlike other effector domains of the multifunctional toxin that target cytoskeleton, the function of alpha-beta hydrolase (ABH) remained elusive. This study demonstrates that AB...

A single intravenous injection of 0.1 mg of heat-killed Bacillus Calmette Guérin (BCG) in 0.1 ml of Bayol F produced an accumulation of activated alveolar macrophages (BCG induced). Cells were collected 3.5-4.0 wk after injection. Phospholipases A and three lysosomal marker enzymes (acid phosphatase, beta-glucuronidase, and lysozyme) were measured in homogenates, and the distribution of the pho...