Cytosolic Phospholipase A2 Type IVA is Present in Human Red Cells

Phospholipase A(2) type IVA (IVAPLA(2)) is a cytosolic enzyme that on activation selectively releases arachidonic acid (AA) from cell membrane phospholipids. Both AA and lysophospholipid, products of the enzymic reaction, can function as signal transducers in cellular interactions. The enzyme is present in most cells, including polymorphs, eosinophils, and platelets. This study used affinity purification to extract IVAPLA(2) from red cell lysate prepared from leukocyte- and platelet-depleted human blood to overcome the masking effect of hemoglobin on Western blot detection. We show that IVAPLA(2) is present in red cells as a 90-kDa protein.