Secretory phospholipase A2

Secretory phospholipase A(2) (sPLA(2)) is a growing family of structurally related, disulfide-rich, low molecular weight, lipolytic enzymes with a His-Asp catalytic dyad. sPLA(2)s are distributed in a wide variety of vertebrate and invertebrate animals, plants, bacteria, and viruses, and there are 10 catalytically active sPLA(2) isozymes in mammals. Although the structural bases for mammalian sPLA(2)s have been well documented, their physiological functions are still subject to debate. Individual mammalian sPLA(2)s have distinct enzymatic properties and display distinct tissue expression patterns, suggesting that each enzyme acts on distinct phospholipid membrane moieties in vivo. In this article, we briefly review our latest understanding of the possible physiological functions of sPLA(2)s, in keeping with their diverse actions on mammalian and nonmammalian cell membranes.