Figure 9. Reverse zymogram of extracellular matrix from the E139K TIMP3 mutant. The left lane demonstrates that the matrix metalloproteinase (MMP) inhibitory activity of the standard purified wild type TIMP3 is retained in both its glycosylated and nonglycosylated forms. Middle lane demonstrates that the TIMP3 E139K mutant also retains MMP inhibitory activity. Right lane represents the expression plasmid of E139K TIMP-3 with a polyhistidine tag, the addition of which resulted in increased molecular weight compared to the untagged construct in the middle lane.