FIGURE 3.

MT6-MMP selectively processes both CXC and CC chemokines. Human or mouse chemokines (1 μg) were incubated at 37 °C for 16 h with recombinant sMT6-MMPΔF in a 10-μl reaction at an enzyme to substrate ratio of 1:10 (w/w). Cleavage assay products of CXCL (A) or CCL (B) chemokines were visualized on silver-stained 15% Tris-Tricine gels. Cleavages of the chemokines listed were not detectable by MALDI-TOF following incubation at a 1:20 molar ratio with sMT6-MMPΔF at 37 °C for 16 h (n > 2). C, cleavage products were assigned by MALDI-TOF mass spectrometry by comparison of measured with predicted mass to charge ratios (m/z) with +1 charge ionization ([M + H]⁺). Cleavage sites are indicated by an arrow in the corresponding sequence.