FIGURE 1.

Cleavage of murine IL-6 by rodent meprin A and meprin B. Homomeric, recombinant mouse meprin A and rat meprin B (0.1 μm) were incubated with murine IL-6 (1 μm) as described under “Materials and Methods.” Both meprin A (A) and meprin B (B) proteolytically cleave murine IL-6 to a smaller product, discernable on 15% SDS-PAGE visualized by Western blotting, upon increasing time of incubation (lanes 1–4). Meprin cleavage of murine IL-6 was prevented when meprin A and meprin B were inhibited by 50 μm actinonin (lane 5). The densitometric loss of the murine IL-6 signal caused by meprin A and densitometric gain of meprin B-generated mIL-6 product from three representative Western blots are plotted (C and D).