Marked Increase of Human Platelet Phospholipase A2 Activity in Vitro and Demonstration of an Endogenous Inhibitor

Overview

Journal Proc Natl Acad Sci U S A

Specialty Science

Date 1983 Sep 1

PMID 6577416

Citations 13

Authors

L R Ballou

W Y Cheung

Affiliations

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Abstract

When soluble and particulate fractions of human platelet homogenate were chromatographed on DEAE-cellulose and hydroxylapatite columns, total phospholipase A2 (PLA2; phosphatide 2-acylhydrolase, EC 3.1.1.4) activity increased sharply. PLA2 activity detected in these partially purified preparations was approximately 12 times greater than that associated with the original homogenate. Chromatography of the particulate enzyme on a DEAE-cellulose column yielded one activity peak. Fractions eluted near the activity peak showed a trace of PLA2 activity but inhibited purified PLA2 stoichiometrically, suggesting the presence of an endogenous "inhibitor" in the homogenate. The inhibitor activity was heat-stable, trypsin insensitive, and extractable by chloroform/methanol, and thus appears to be associated with a lipid(s). PLA2 activity was Ca2+ dependent. The crude enzyme was variably stimulated by calmodulin, whereas the purified enzyme was not, suggesting that the effect of calmodulin on the crude enzyme is indirect. Our results suggest that human platelet PLA2 activity reported in the literature may have been underestimated, apparently due to the presence of an endogenous inhibitor.

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References

LOWRY O, ROSEBROUGH N, FARR A, RANDALL R . Protein measurement with the Folin phenol reagent. J Biol Chem. 1951; 193(1):265-75. View

Imai A, Ishizuka Y, Kawai K, Nozawa Y . Evidence for coupling of phosphatidic acid formation and calcium influx in thrombin-activated human platelets. Biochem Biophys Res Commun. 1982; 108(2):752-9. DOI: 10.1016/0006-291x(82)90893-2. View

Patriarca P, Beckerdite S, Pettis P, Elsbach P . Phospholipid metabolism by phagocytic cells. VII. The degradation and utilization of phospholipids of various microbial species by rabbit granulocytes. Biochim Biophys Acta. 1972; 280(1):45-56. View

Franson R, Patriarca P, Elsbach P . Phospholipid metabolism by phagocytic cells. Phospholipases A2 associated with rabbit polymorphonuclear leukocyte granules. J Lipid Res. 1974; 15(4):380-8. View

Michell R . Inositol phospholipids and cell surface receptor function. Biochim Biophys Acta. 1975; 415(1):81-47. DOI: 10.1016/0304-4157(75)90017-9. View

Derksen A, Cohen P . Patterns of fatty acid release from endogenous substrates by human platelet homogenates and membranes. J Biol Chem. 1975; 250(24):9342-7. View

Bills T, Smith J, Silver M . Metabolism of [14C]arachidonic acid by human platelets. Biochim Biophys Acta. 1976; 424(2):303-14. DOI: 10.1016/0005-2760(76)90198-3. View

PICKETT W, Jesse R, Cohen P . Initiation of phospholipase A2 activity in human platelets by the calcium ion ionophore A23187. Biochim Biophys Acta. 1976; 486(1):209-13. DOI: 10.1016/0005-2760(77)90086-8. View

Samuelsson B, Goldyne M, Granstrom E, Hamberg M, Hammarstrom S, Malmsten C . Prostaglandins and thromboxanes. Annu Rev Biochem. 1978; 47:997-1029. DOI: 10.1146/annurev.bi.47.070178.005025. View

10.

. Production of diglyceride from phosphatidylinositol in activated human platelets. J Clin Invest. 1979; 63(4):580-7. PMC: 371991. DOI: 10.1172/JCI109339. View

11.

Bell R, Kennerly D, Stanford N, MAJERUS P . Diglyceride lipase: a pathway for arachidonate release from human platelets. Proc Natl Acad Sci U S A. 1979; 76(7):3238-41. PMC: 383799. DOI: 10.1073/pnas.76.7.3238. View

12.

Wong P, Cheung W . Calmodulin stimulates human platelet phospholipase A2. Biochem Biophys Res Commun. 1979; 90(2):473-80. DOI: 10.1016/0006-291x(79)91259-2. View

13.

Jesse R, Franson R . Modulation of purified phospholipase A2 activity from human platelets by calcium and indomethacin. Biochim Biophys Acta. 1979; 575(3):467-70. DOI: 10.1016/0005-2760(79)90117-6. View

14.

Bell R, MAJERUS P . Thrombin-induced hydrolysis of phosphatidylinositol in human platelets. J Biol Chem. 1980; 255(5):1790-2. View

15.

. Indomethacin-induced accumulation of diglyceride in activated human platelets. The role of diglyceride lipase. J Biol Chem. 1980; 255(6):2259-62. View

16.

Broekman M, Ward J, Marcus A . Phospholipid metabolism in stimulated human platelets. Changes in phosphatidylinositol, phosphatidic acid, and lysophospholipids. J Clin Invest. 1980; 66(2):275-83. PMC: 371708. DOI: 10.1172/JCI109854. View

17.

Billah M, Lapetina E, Cuatrecasas P . Phospholipase A2 and phospholipase C activities of platelets. Differential substrate specificity, Ca2+ requirement, pH dependence, and cellular localization. J Biol Chem. 1980; 255(21):10227-31. View

18.

McKean M, Smith J, Silver M . Formation of lysophosphatidylcholine by human platelets in response to thrombin. Support for the phospholipase A2 pathway for the liberation of arachidonic acid. J Biol Chem. 1981; 256(4):1522-4. View

19.

Lapetina E, Billah M, Cuatrecasas P . The initial action of thrombin on platelets. Conversion of phosphatidylinositol to phosphatidic acid preceding the production of arachidonic acid. J Biol Chem. 1981; 256(10):5037-40. View

20.

Hirata F . The regulation of lipomodulin, a phospholipase inhibitory protein, in rabbit neutrophils by phosphorylation. J Biol Chem. 1981; 256(15):7730-3. View