A Novel Bifunctional Mechanism of Surface Recognition by Phospholipase A₂

Abstract

The dedication of yet another volume to the subject of the phospholipases A₂ (PLA₂) attests to the continued high level of interest in these enzymes. As will be evident from the articles contained herein, a major focus of interest is in regard to the involvement of PLA₂ in the initiation of a metabolic cascade leading to the production of potent mediators of inflammatory diseases. Accordingly, an active search is underway for modulators or inhibitors of enzyme activity that might be useful in the treatment of inflammation, asthma, etc.. Furthermore, from a purely mechanistic point of view, the PLA₂ have always been prime subjects for the study of interfacial catalysis. These enzymes are small, water soluble, stable, and work alone with only a requirement for calcium in their hydrolysis of water-insoluble phospholipids. Also, in contrast to the substrates of other lipolytic enzymes, phospholipids lend themselves ideally to such studies in that they form a variety of stable and structurally well-defined surfaces in micelles, reverse micelles, monolayers, planar bilayers, and curved vesicles with which to study catalysis at the boundary between two phases.