A Ca2+-independent phospholipase A that releases various fatty acids from sn-1 and sn-2 positions was partially purified from rat brain soluble fraction. The enzyme showed an approximate molecular mass of 300 kDa on gel filtration column chromatography. Its enzymatic properties are distinct from those of well characterized phospholipase A2 enzymes; by using a series of synthetic phosphatidylcholines, the enzyme cleaved oleic, linoleic, and arachidonic acids like phospholipase A2, and released palmitic and stearic acids like phospholipase A1.
Phosphatidylcholine, phosphatidylethanolamine, phosphatidylinositol, and phosphatidic acid were hydrolysed with almost equal efficiencies by this enzyme. These results indicate that the enzyme isolated is a novel Ca2+ -independent intracellular phospholipase A that might be responsible for production of various fatty acids from membrane phospholipids.
AsaokaYOkaMYoshidaKSasakiYNishizukaY.Role of lysophosphatidylcholine in T-lymphocyte activation: Involvement of phospholipase A2 in signal transduction through protein kinase C. Proc Natl Acad Sci USA1992; 89: 6447–51.
4.
YoshidaKAsaokaYNishizukaY.Platelet activation by simultaneous actions of diacylglycerol and unsaturated fatty acids. Proc Natl Acad Sci USA1992; 89: 6443–6.
DennisEA. Diversity of group types, regulation. and function of phospholipase A2. J Biol Chem1994; 269: 13057–60.
7.
ClarkJDMilonaNKnopfJL. Purification of a 110-kilodalton cytosolic phospholipase A2 from the human monocytic cell line U937. Proc Natl Acad Sci USA1990; 87: 7708–12.
8.
KramerRMRobertsEFManettaJPutnamJE. The Ca2+-sensitive cytosolic phospholipase A2 is a 100-kDa protein in human monoblast U937 cells. J Biol Chem1991; 266: 5268–72.
9.
HazenSLStuppyRJGrossRW. Purification and characterization of canine myocardial cytosolic phospholipase A2. A calcium-independent phospholipase with absolute sn-2 regiospecificity for diradyl glycerophospholipids. J Biol Chem1990: 265: 10622–30.
10.
RamanadhamSWolfMJJettPAGrossRWTurkJ.Characterization of an ATP-stimulatable Ca2+-independent phospholipase A2 from clonal insulin-secreting HIT cells and rat pancreatic islets: A possible molecular component of the beta-cell fuel sensor. Biochemistry1994; 33: 7442–52.
11.
AckermannLJKempnerESDennisEA. Ca2+-independent cytosolic phospholipase A2 from macrophage-like P388D1 cells. Isolation and characterization. J Biol Chem1994; 269: 9227–33.
12.
AckermanLJConde-FrieboesKDennisEA. Inhibition of macrophage Ca24-independent phospholipase A2 by bromoenol lactone and trifluoromethyl ketones. J Biol Chem1995; 270: 445–50.
13.
BroekmanMJWardJWMarcusAJ. Fatty acid composition of phospatidylinositol and phosphatidic acid in stimulated platelets. Persistence of arachidonyl-stearyl structure. J Biol Chem1981; 256: 8271–4.
14.
KatsuraKTurcoEBRFolbergrovaJBazanNGSiesjöBK. Coupling among energy failure, loss of ion homeostasis, and phospholipase A2 and C activation during ischemia. J Neurochem1993; 61: 1677–84.
15.
VisioliFRihnLLTurcoEBRKreismanNRBazanNG. Free fatty acid and diacylglycerol accumulation in the rat brain during recurrent seizures is related to cortical oxygenation. J Neurochem1993; 61: 1835–42.
16.
TsujishitaYAsaokaYNishizukaY.Regulation of phospholipase A2 in human leukemia cell lines: Its implication for intracellular signaling. Proc Natl Acad Sci USA1994; 91: 6274–8.
17.
DoleVPMeinertzH.Microdetermination of long-chain fatty acids in plasma and tissues. J Biol Chem1960; 235: 2595–9.
18.
BartfaiT.Preparation of metal-chelate complexes and the design of steady-state kinetic experiments involving metal nucleotide complex. Adv Cyclic Nucleotide Res1979; 10: 219–42.
19.
BlighEGDyerWJ. A rapid method of total lipid extraction and purification. Can J Biochem Physiol1959; 37: 911–7.
20.
BarkerSAMontiJAChristianSTBeningtonFMorinRD. 9-Diazomethylanthracene as a new fluorescence and ultraviolet label for the spectrometric detection of picomole quantities of fatty acids by high-pressure liquid chromatography. Anal Biochem1980; 107: 116–23.
21.
BradfordMM. A rapid and sensitive method for the quantitation of microgram quantities of protein utilizing the principle of protein dye binding. Anal Biochem1976; 72: 248–54.
22.
HirashimaYFarooquiAAMillsJSHorrocksLA. Identification and purification of calcium-independent phospholipase A2 from bovine brain cytosol. J Neurochem1992; 59: 708–14.
23.
WangRDodiaCRJainMKFisherAB. Purification and characterization of a calcium-independent acidic phospholipase A, from rat lung. Biochem J1994; 304: 131–7.
24.
PetitKDe BlockJDe PotterW.Isolation and characterization of a cytosolic phospholipase A2 from bovine adrenal medulla. J Neurochem1995; 64: 139–46.
25.
ThomsonFJClarkMA. Purification of a phosphatidic-acid-hydrolysing phospholipase A2 from rat brain. Biochem J1995; 306: 305–9.
26.
PortillaDDaiG.Purification of a novel calcium-independent phospholipase A2 from rabbit kidney. J Biol Chem1996; 271: 15451–7.
27.
PierikAJNijssenJGAarsmanAJvan den BoschH.Calcium-independent phospholipase A2 in rat tissue cytosols. Biochem Biophys Acta1988; 962: 345–53.
28.
RookeJAWebsterGR. Phospholipase A in human brain: A1-type at alkaline pH. J Neurochem1976; 27: 613–20.
29.
UedaHKobayashiTKishimotoMTsutsumiTWatanabeSOkuyamaH.The presence of Ca2+-independent phospholipase A, highly specific for phosphatidylinositol in bovine brain. Biochem Biophys Res Commun1993; 195: 1272–9.
30.
PeteMJRossAHExtonJH. Purification and propeties of phospholipase A, from bovine brain. J Biol Chem1994; 269: 19494–500.
31.
PeteMJWuDWExtonJH. Subcellular fractions of bovine brain degrade phosphatidylcholine by sequential deacylation of the sn-1 and sn-2 positions. Biochim Biophys Acta1996; 1299: 325–32.
32.
NalboneGHostetlerKYLeonardiJTrotzMLafontH.Partial characterization of rat heart cytosolic phospholipase A, and demonstration of essential sulfhydryl groups. Biochim Biophys Acta1986; 877: 88–95.
33.
CaoYZTarnSWArthurGChenHChoyPC. The purification and characterization of a phospholipase A in hamster heart cytosol for the hydrolysis of phosphatidylcholine. J Biol Chem1987; 262: 16927–35.
34.
DawsonRMIrvineRFHemingtonNLHirasawaK.The alkaline phospholipase A1 of rat liver cytosol. Biochem J1983; 209: 865–72.
35.
HiggsHNGlomsetJA. Purification and properties of a phosphatidic acid-preferring phospholipase A1 from bovine testis. Examination of the molecular basis of its activation. J Biol Chem1996; 271: 10874–83.
36.
HanelAMGelbMH. Multiple enzymatic activities of the human cytosolic 85-kDa phospholipase A2: Hydrolytic reactions and acyl transfer to glycerol. Biochemistry1995; 34: 7807–18.
