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Catalytic mechanism and function of phosphatidate-specific phospholipases A2

Research Project

Project/Area Number 11670120
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field General medical chemistry
Research InstitutionOsaka University

Principal Investigator

TOJO Hiromasa  Osaka University Graduate School of Medicine, Associate Professor, 医学系研究科, 助教授 (90135707)

Project Period (FY) 1999 – 2000
Project Status Completed (Fiscal Year 2000)
Budget Amount *help
¥3,900,000 (Direct Cost: ¥3,900,000)
Fiscal Year 2000: ¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1999: ¥2,500,000 (Direct Cost: ¥2,500,000)
Keywordsphospholipase A2 / phosphatidic acid / lysobisphosphatidic acid / monoacylglycerollipase / phospholipids / testis / lysophosphatidic acid / リパーゼ
Research Abstract

A phospholipase A2 (PLA2) was purified to homogeneity from the supernatant fraction of rat testis homogenate. The purified 63-kDa enzyme did not require Ca^<2+> ions for activity, and exhibited both phosphatidic acid-preferring PLA2 and monoacylglycerol lipase (MGL) activities with a modest specificity toward unsaturated acyl chains, but not lysophospholipase, and di- and triacylglycerol lipase activities. Anionic detergents enhanced these activities. Serine-modifying irreversible inhibitors, (p-amidino)-phenylmethanesulfonyl fluoride and methylarachidonyl fluorophosphonate inhibited both activities to a similar extent, indicating a single active site is involved in PLA2 and MGL catalysis. We sequenced about 10 tryptic peptides of PA-PLA2 by capillary reverse phase HPLC/electrospray ionization (ESI) ion trap mass spectrometry, and found that it belonged to a new family of PLA2 enzymes. The optimal pH for PLA_2 activity (around 5.5) differed from that for MGL activity (around 8.0), but both activities broadly extended over a physiologically relevant pH range from pH 5.5 to 7.5. At pH 5.5 the enzyme also hydrolyzed bis (monoacylglycerol) phosphate (lysobisphosphatidic acid, LBPA) that has been hitherto known as a PLA2-resistant phospholipid and a late endosome marker. LBPA-enriched fractions were prepared from crude liver lysosome fractions of chloroquine-treated rats, treated with excess of pancreatic PLA2, and then used for assaying LBPA-hydrolyzing activity. LBPA and the reaction products were identified by microbore normal-phase HPLC/ESI ion-trap mass spectrometry. These enzymatic properties suggest that the enzyme can metabolize phosphatidic acid, lysobisphosphatidic acid, and monoacylglycerol in the endosome/lysosome system with mildly acidic milieu.

Report

(3 results)
  • 2000 Annual Research Report   Final Research Report Summary
  • 1999 Annual Research Report
  • Research Products

    (17 results)

All Other

All Publications (17 results)

  • [Publications] Ting Lu: "Identification of Essential Residues for Catalysis of Rat Intestinal Phospholipase B/Lipase"Biochemistry. (印刷中). (2001)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Urbain Tchoua: "Increased intestinal phospholipase A_2 activity catalyzed by phospholipase B/lipase in WBN/Kob rats with pancreatic insufficiency"Biochim.Biophys.Acta. 1487. 255-267 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Nakajima,T.: "Phospholipase A2-mediated superoxide production of murine peritoneal macrophages induced by chrysotile stimulation"Int.J.Biochem.Cell Biol.. 32. 779-787 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Koyama,M.: "Elevation of group II phospholipase A2 in serum and amniotic fluid in preterm labor"Am.J.Obstet.Gynecol.. 183. 1537-1543 (2000)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Sawaguchi,A.: "Reappraisal of polassium permanganate oxidation applied to lowicryl K4M embedded tissues processed by high pressure freezing/freeze substitution, with special reference to differential staining of the zymogen granules of rat gastric chief cells"Arch.Histol.Cytol.. 62. 447-458 (1999)

    • Description
      「研究成果報告書概要(和文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Lu, T., Ito, M., Tchoua, U., Takemori, H., Okamoto, M., and Tojo, H.: "Identification of Essential Residues for Catalysis of Rat Intestinal Phospholipase B/Lipase"Biochemistry. (In press). (2001)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Tchoua, U., Ito, M., Okamoto, M., and Tojo, H.: "Increased intestinal phospholipase A_2 activity catalyzed by phospholipase B/lipase in WBN/Kob rats with pancreatic insufficiency"Biochim.Biophys.Acta. 1487. 255-267 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Nakajima, T., Ito, M., Tchoua, U., Tojo, H., and Hashimato, M.: "Phospholipase A2-mediated superoxide production of murine peritoneal macrophages induced by chrysotile stimulation"Int.J.Biochem.Cell Biol.. 32. 779-787 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Koyama, M., Ito, S., Nakajima, A., Shimoya, K., Azuma, C., Suehara, N., Murata, Y., and Tojo, H.: "Elevation of group II phospholipase A2 in serum and amniotic fluid in preterm labor"Am.J.Obstet.Gynecol.. 183. 1537-1543 (2000)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Sawaguchi, A., Ide, S., Kawano, J., Nagaike, R., Oinuma, T., Tojo, H., Okamoto, M., and Suganuma, T.: "Reappraisal of potassium permanganate oxidation applied to lowicryl K4M embedded tissues processed by high pressure freezing/freeze substitution, with special reference to differential staining of the zymogen granules of rat gastric chief cells"Arch.Histol.Cytol.. 62. 447-458 (1999)

    • Description
      「研究成果報告書概要(欧文)」より
    • Related Report
      2000 Final Research Report Summary
  • [Publications] Urbain Tchoua: "Increased intestinal phospholipase A_2 activity catalyzed by phospholipase B/lipase in WBN/Kob rats with pancreatic insufficiency"Biochim.Biophys.Acta. 1487. 255-267 (2000)

    • Related Report
      2000 Annual Research Report
  • [Publications] Ting Lu: "Identification of Essential Residues for Catalysis of Rat Intestinal Phospholipase B/Lipase"Biochemistry. (印刷中).

    • Related Report
      2000 Annual Research Report
  • [Publications] Nakajima T.: "Phospholipase A2-mediated superoxide production of murine peritoneal macrophages induced by chrysotile stimulation"Int. J. Biochem. Cell Biol.. (印刷中). (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] Koyama M.: "Elevation of group II phospholipase A2 in serum and amniotic fluid in preterm labor"Am. J. Obstet. Gynecol.. (印刷中). (2000)

    • Related Report
      1999 Annual Research Report
  • [Publications] Sawaguchi A.: "Reappraisal of potassium permanganate oxidation to lowicryl K4M embedded tissues processed by high pressure freezing/freeze substitution, with special reference to diffential staining of the zymogen granules of rat gastric chief cells"Arch. Histol. Cytol.. 62. 447-458 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] Nakagawa M.: "A prespore-cell-inducing factor in Dictyostelium discoideum: its purification and characterization"Biochem. J.. 343. 265-271 (1999)

    • Related Report
      1999 Annual Research Report
  • [Publications] 東城博雅: "新しいリパーゼファミリーに属するホスホリパーゼB/リパーゼ"蛋白質核酸酵素. 44. 1032-1037 (1999)

    • Related Report
      1999 Annual Research Report

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Published: 1999-04-01   Modified: 2016-04-21  

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