Introduction The phospholipase C (PLC) class of enzymes has attracted intense interest in the biological and chemical communities because of the central role these enzymes play in the regulatory functions related to agonist- receptor interaction and transmembrane ~ignaling.l-~ In the first stage of this process, agonists including hor- mones, neurotransmitters, and some growth factors bind to a Gprotein linked receptor in the membrane to initiate a cascade that leads to the ...