Coupling of the i-face and the active site of phospholipase A2 for interfacial activation

Interfacial enzymes bind to organized interfaces where they access their substrates. As an example of interfacial activation, phospholipase A2 has an observed rate of hydrolysis of the sn-2-acyl chain of phospholipids at bilayer and micellar interfaces that is more than 1,000 times larger than with monodisperse phospholipids. The major challenge for the study of interfacial enzymes is to correlate the elementary steps of the interfacial function of the enzyme with the structure of the enzyme at the interface. Having kinetically resolved the steps of the interfacial turnover cycle, here we outline our recent (mostly since 2000) approaches to address remaining issues of interfacial activation and also the protocols that are likely to provide insights into the distinguishing structural features of the interface-activated enzyme.