GENERATION AND ACTIVITY OF THE TERNARY GELATINASE-B TIMP-1 LMW-STROMELYSIN-1 COMPLEX

Incubation of progelatinase B, isolated from human polymorphonuclear leukocytes, with TIMP-1 leads to the formation of the progelatinase B/TIMP-1 complex, This complex behaves like a Janus in a similar manner as we previously described for the progelatinase A/TIMP-2 complex. It shows the properties of TIMP-1 and is a better inhibitor for gelatinase A than for gelatinase B. Treatment with trypsin leads to activation of the binary complex, The activity, however amounts only to slightly more than 10% of the activity of free gelatinase B, not complexed with TIMP-1. When the progelatinase B/TIMP-1 complex inhibits an active matrix metalloproteinase, a ternary complex is generated that after activation displays a distinct higher proteolytic activity than the active binary complex, The active binary complex cannot be transformed into the active ternary complex.