A novel method for measuring protein kinase C activity in a native membrane-associated state.

Physiological activation of protein kinase C (PKC) is believed to occur by redistributing soluble enzyme to the phospholipid environment of membranes. Currently available in vitro methods of measuring PKC activation all involve prior extraction of membrane-associated enzyme and its reconstitution in an artificial phospholipid environment or modification (such as partial trypsinization) of the enzyme itself. Here we report a novel method which, for the first time, allows measurement of active PKC still in its native, membrane-associated state using a specific, physiological substrate. Thus, with this new method PKC activity can be measured while still in an environment that approximates the in vivo situation.