allosteric kinase inhibitor

An allosteric kinase inhibitor switches off a kinase by binding somewhere other than the spot where it does its chemistry. Most kinase drugs plug the ATP-binding site, the slot where the enzyme grabs its energy molecule. An allosteric inhibitor instead grips a different pocket on the protein and, by changing the protein's shape, jams the enzyme — like locking a machine by wedging its hinge rather than blocking the part that actually cuts.

This indirect approach has real advantages. The ATP site looks almost the same across hundreds of kinases, so ATP-competitive drugs struggle to be selective; allosteric pockets are far more distinctive, so a drug that binds one can leave related kinases untouched. Allosteric inhibitors can also sidestep resistance mutations that arise in the ATP site, and they can stabilize a particular inactive shape of the enzyme to hold it firmly off.

The catch is that suitable allosteric pockets are rare and hard to find, and they are usually shallower or less obviously functional than the ATP site, making them tougher to drug. When one does exist, though, an allosteric kinase inhibitor can deliver the selectivity and resistance-beating profile that an ATP-site drug cannot.