Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9442999 | Experimental Parasitology | 2005 | 8 Pages |
Abstract
Phosphatidylcholine (PC)-specific phospholipase D (PC-PLD) and phosphatidylcholine (PC)-specific phospholipase C (PC-PLC) activities have been detected in Uronema marinum. Partial purification of PC-PLC revealed that two distinct forms of PC-PLC (named as mPC-PLC and cPC-PLC) were existed in membrane and cytosol fractions. The two PC-PLC enzymes showed the preferential hydrolyzing activity for PC with specific activity of 50.4 for mPC-PLC and 28.3Â pmol/min/mg for cPC-PLC, but did not hydrolyze phosphatidylinositol or phosphatidylethanolamine. However, the biochemical characteristics and physiological roles of both enzymes were somewhat different. mPC-PLC had a pH optimum in the acidic region at around, pH 6.0, and required approximately 0.4Â mM Ca2+ and 2.5Â mM Mg2+ for maximal activity. cPC-PLC had a pH optimum in the neutral region at around, pH 7.0, and required 1.6Â mM Ca2+ and 2.5Â mM Mg2+ for maximal activity. cPC-PLC, but not mPC-PLC, showed a dose-dependent inhibitory effect on the luminal-enhanced chemiluminescence (CL) responses and the viability of zymosan-stimulated phagocytes of olive flounder, indicating that cPC-PLC may contribute to the parasite evasion against the host immune response. Our results suggest that U. marinum contains PC-PLD as well as two enzymatically distinct PC-PLC enzymes, and that mPC-PLC may play a role in the intercellular multiplication of U. marinum and cPC-PLC acts as a virulence factor, serving to actively disrupt the host defense mechanisms.
Keywords
ethylene glycol-bis(β-aminoethylether)-N,N,N′,N′-tetraacetic acidScuticociliatosisPIP2ScuticociliatePC-PLCUronema marinumPMSFMS-222HBSSPEtOHEGTATLCDTTROIsphosphatidic acidtricaine methanesulfonatediacylglyceroldipalmitoylphosphatidylcholinedithiothreitolDAGphosphatidylinositolphosphatidylcholinePhosphatidylcholine-specific phospholipase CphosphatidylethanolaminePhosphatidylserinephosphatidylethanolphosphatidylinositol-(4,5)-bisphosphatephenylmethylsulfonyl fluorideHanks’ balanced salt solutionReactive oxygen intermediateshigh performance liquid chromatographyHPLCthin-layer chromatography
Related Topics
Life Sciences
Immunology and Microbiology
Parasitology
Authors
Jung Soo Seo, Moo Sang Kim, Sang Hwan Lee, Ki Hong Kim, Hyung Ho Lee, Hyun Do Jeong, Joon Ki Chung,