Purification and characterization of human platelet phospholipase A2 which preferentially hydrolyzes an arachidonoyl residue

FEBS Letters

Takayama, Kiyoshi²  Inoue, Keizo²  Nozawa, Yoshinori¹  Kim, Dae Kyong²  Nagata, Koichi¹  Kudo, Ichiro² 

[1]School of Medicine, Gifu University, Tsukasa-cho, Gifu, Gifu 500, Japan

[2]Faculty of Pharmaceutical Sciences, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113, Japan

关键词: Phospholipase A2;    Human platelet;    Calcium ion;    GPC;    glcerophosphocholine;    GPE;    glycerophosphoethanolamine;    PC;    phosphatidylcholine;    PE;    phosphatidylethanolamine;   

DOI  :  10.1016/0014-5793(91)80506-X

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

A phospholipase A₂ with an arachidonoyl residue preference was purified about 11 700-fold from human platelet soluble fraction to near homogeneity. The purified phospholipase A₂ exhibited a molecular mass of about 90 kDa on SDS polycrylamide gel electrophoresis and hydrolyzed phospholipids with a arachidonoyl residue more effectively than those with a linoleoyl residue. The catalytic activity of the purified enzyme detected with phosphatidylcholine as a substrate increased sharply between 3 × 10⁻⁷ and 10⁻⁶ M free calcium ion. Thus, the 90-kDa phospholipase A₂ is considered to be a novel enzyme, distinct from the 14-kDa one previously purified from human platelets. The 90-kDa phospholipase A₂ may participate mainly in arachidonate metabolism of platelets.

【 授权许可】

Unknown