What are activation mechanisms of matrix metalloproteinases (MMPs)?

ProMt-MMP is activated during the transport to the cell surface by a furin-like serine protease, by non-proteolytic conformational changes, or at the cell surface by plasmin. The activated MT-MMP then becomes inhibited by TIMP2. The hemopexin domain of ProMMP2 then binds to the C-terminal component of TIMP 2 to create a trimolecular complex. Previously uninhibited MT-MMP then partially activates the ProMMP2 by separating most of the MMP2 propeptide. The remaining component of the propeptide is removed by a separate cell surface MMP2 molecule to create a fully mature MMP2.  The mature MMP2 can be released from the cell surface or be inhibited by a different TIMP molecule. It can also be bound by another cell surface MMP2 protein or left in an uninhibited active state.