Calcium is sufficient but not necessary for activation of sheep platelet cytosolic phospholipase A2

FEBS Letters

Zupan, Lori A.¹  Gross, Richard W.¹  Kruszka, Kelly K.¹ 

[1] Molecular and Cellular Cardiovascular Biochemistry Section, Washington University School of Medicine, St. Louis, MO 63110, USA

关键词: Phospholipase A2;    Calcium;    Platelet;    Arachidonic acid;    Plasmalogen;   

DOI  :  10.1016/0014-5793(91)80753-P

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In this study we demonstrate that: (1) although the major phospholipase A₂ present in sheep platelets is activated by calcium ions, it can effectively catalyze hydrolysis of the sn-2 ester linkage in phospholipids in the absence of calcium: (2) expression of calcium-independent phospholipase A₂ activity can be induced by NACl utilizing purified (but not crude) cytosolic enzyme; and (3) calcium-independent phospholipase A₂ activity is regulated by a reconstitutable cytosolic protein. Collectively, these results underscore the fundamental catalytic differences between extracellular and intracellular calcium-dependent phospholipases A₂ and demonstrate that calcium is sufficient, but not necessary, for the activation of this class of intracellular phospholipases A₂

【 授权许可】

Unknown