Structural and functional properties of a phospholipase A2 purified from an inflammatory exudate.

The cell-free supernatant of sterile inflammatory peritoneal exudates contains a phospholipase A2 that participates in the digestion of Escherichia coli killed by polymorphonuclear leukocytes or by the purified bactericidal/permeability increasing protein (BPI) of these cells. This phospholipase A2 has been purified, and the sequence of the NH2-terminal 39 amino acids has been determined and compared with sequences of both BPI-responsive and BPI-nonresponsive phospholipases A2 from snake venoms and mammalian pancreas. The high concentration and location of basic residues in the NH2-terminal region is a common feature of BPI-responsive phospholipases A2 and may characterize those phospholipases A2 participating in inflammatory events.