Production and activity assays of recombinant Spd-1, Spd-2, and polyserase-3. A, 5 μL of bacterial extract transformed with the plasmids pGEX-Spd1 (lane3), pGEX-Spd2 (lane 5) and pGEX-pol3 (lane 9), and the corresponding purified fusion proteins (Spd1, lane 4; Spd2, lane 6, and polyserase3, lane 10). Lane 2, bacterial extract transformed with an empty pGEX-2TK. Lanes 7 and 8 correspond to induction and purification of ADAM23 disintegrin domain, respectively. Lane 1, molecular size markers, whose sizes in kDa are indicated on the left. B, Western blot analysis of the purified fusion proteins using an anti GST antibody. C, degradation of fibrinogen by the indicated fusion proteins. C, control, corresponds to incubation of fibrinogen without any recombinant protein. D, Inhibition analysis of polyserase-3 after preincubation with AEBSF (0.1 mM), EDTA (2 mM) and E-64 (10 μM). E, digestion of pro-uPA by purified polyserase-3. C indicates incubation of pro-uPA alone. F, incubation of different extracellular proteins with purified polyserase-3.