Figure 1:

Specific labeling of active MMP-14 using protein engineering coupled with ABPs. a) Engineered MMP-14 contains a cysteine nucleophile that is irreversibly labeled by the ABP. Covalent binding occurs only with the active form of MMP-14 following affinity targeting of the catalytic zinc by the hydroxamate-containing ABP, but not with the proenzyme or the inhibited form in which the zinc is inaccessible. b) ABP labeling is selective to the probe sensitive MMP while any interactions with native MMPs result in reversible weak inhibition.