MMP-12 is secreted as a 54-kd pro-form protein that undergoes self-activation through autolytic processing to produce 45- and 22-kd active forms of the enzyme.

• MMP-12以酶原（54kd）的形式分泌出来，再通过自身激活途径催化产生45kd和22kd的两种活性形式。