Phospholipases, enzymes that share a substrate class.

Considerable work has gone into the study of PLs since the first suggestions of their existence nearly a century ago. This work has intensified enormously since the mid-1970s when their role in signal-coupling mechanisms and in pathophysiology was recognized. While much has been done to understand this diverse group of enzymes at the molecular and mechanistic levels, the discovery of new PLs has far outstripped our capacity to study them in sufficient detail to appreciate what makes each unique while perhaps having some common mechanisms of action and regulation. One would almost plead: No new PLs - Let us study those at hand! That is not the case in our field and the discovery of new PLs will continue. It is important, however, that an understanding be gained of these enzymes at the molecular level, how they interact with their substrates, and how regulatory factors can target the function of PLs in situ.