The pathogenesis and pathophysiology of Acanthamoeba infections remain incompletely understood. Phospholipases are known to cleave phospholipids, suggesting their possible involvement in the host cell plasma membrane disruption leading to host cell penetration and lysis. The aims of the present study were to determine phospholipase activities in Acanthamoeba and to determine their roles in the ...

It is known that His-48 is part of the active center in pancreatic phospholipase. To further elucidate the role of histidine-48 in the active center of pancreatic phospholipase A2, we have modified the enzyme with a number of bromo ketones and methyl benzenesulfonates. Rapid methylation occurred with methyl p-nitrobenzenesulfonate. Methylated phospholipase shows total loss of enzymatic activity...

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A phospholipid mixture was isolated from bovine vesicle tissue. This phospholipid preparation contained the following prostaglandin precursor fatty acids: 4.7 percent 5,8,11-eicosatrienoic acid, 9.1 percent 5,8,11,14-eicosatetraenoic acid and 0.9% 5,8,11,14,17-eicosapentaenoic acid. With this phospholipid preparation as substrate phospholipase activity could be detected in different fractions o...

abstract background and objective: snake venom is a complex of several toxic elements and enzymes. it has the agents with the ability to destroy cellular and subcellular membrane and to bring about hemolysis of red blood cells (rbc). two types of direct and indirect hemolytic activity are known in snake venom in that phospholipase a2 is responsible for the indirect lysis. the aim of this study ...

The human serotonin 5-HT2C receptor undergoes adenosineto-inosine RNA editing at five positions, generating multiple receptor isoforms with altered G-protein coupling properties. In the current study, we demonstrate that RNA editing regulates the pattern of intracellular signaling. The non-edited human 5-HT2C receptor isoform INI activates phospholipase D via the G13 heterotrimer G-protein. We ...

The preceding paper describes purification and properties of a 150-kDa polyphosphoinositide-specific phospholipase C from a cytosolic fraction of turkey erythrocytes (Morris, A. J., Waldo, G. L., Downes, C. P., and Harden, T. K. (1990) J. Biol. Chem. 265, 13501-13507). Turkey erythrocytes express a PZupurinergic receptor that employs an unidentified Gprotein to activate phospholipase C (Boyer, ...

Three different mechanisms have been detected for the aggregation of platelets by tumor cells in a homologous human system based on inhibition studies with apyrase, hirudin, and phospholipase D. In the major group, platelet aggregation induced by the SKBR3 (adenocarcinoma), SKNMC (neuroblas toma), HT29 (adenocarcinoma), and HT144 (melanoma) cell lines was inhibited by apyrase and phospholipase ...

The infection of HeLa cells by poliovirus leads to profound alterations in the activities of both phospholipase C and the A23187-stimulated phospholipase A2. As early as the third hour after poliovirus infection, the activity of phospholipase C is enhanced, as measured by the increase in inositol triphosphate (IP3) in the cells. By the fifth hour post-infection there is a 5-fold increase in IP3...

Fourteen isolates of Corynebacteruim pseudotuberculosis of them 7 were isolated from sheep with Caseous Lymphadenitis "biotype 1" and 7 isolated from buffaloes with Oedematous Skin Disease "biotype 2". All isolates were identified by standard microbiological techniques and by polymerase chain reaction targeting, 16S rRNA and phospholipase D genes. Synergistic haemolytic titers of all isolates w...