FIGURE 4.

All MMPs evaluated precisely cleaved CCL23 at one or more sites. Human CCL23-(1–99) was incubated with recombinant MMP-1, -2, -3, -7, -8, -9, -12, -13, and -14 for 16 h at 37 °C. A, cleavage products were assigned by MALDI-TOF MS by comparison of measured with predicted mass-to-charge ratios (m/z) with a +1 charge ionization ([M + H]⁺). Corresponding sequences are shown. B, cleavage assay products were visualized on silver-stained 15% Tris-Tricine gels. C, mass spectra of cleavage assay products of CCL23 in the absence (left) or presence (right) of MMP-12 show that the predominant truncated form CCL23-(26–99) is present in the form used for functional assays.