3.4.24.7 5.8 9 pH 5.8: about 30% of maximal activity, pH 9.0: about 45% of maximal activity 95828 3.4.24.7 6 9.2 degradation of collagen I: at pH 7.5 a 10fold higher activity is observed toward the alpha-2 chain, whereas a very similar value for the two chains is detected at pH 7.0. At pH lower 7.0 the overall enzymatic activity toward the alpha-1 chain increases, whereas the processing of the alpha-2 chain remains essentially constant between pH 7.3 and 6.0 717876 3.4.24.7 6 9.2 degradation of collagen I: over the whole pH range investigated the proteolytic activity on the alpha2 chains is higher than for the alpha1 chain. Difference is large at alkaline pH (40fold at pH 9.2) and it decreases as the pH decreases toward the physiological value where the enzymatic processing of the alpha2 chain is only 4times higher than for the alpha1 chain. Difference remains essentially unchanged down to pH 6.3 717876 3.4.24.7 6 9.2 degradation of synthetic substrate is pH-independent 717876 3.4.24.7 6 9.2 degradation of synthetic substrate: overall enzymatic activity of ect-MMP-14 displays a pH dependence characterized by maximum efficiency at pH 7.0, which decreases upon both pH increase and pH decrease 717876 3.4.24.7 6.5 9.5 pH 6.5: about 65% of maximal activity, pH 9.5: about 60% of maximal activity 95826 3.4.24.7 7 9.8 about 70% of maximal activity at pH 7.0 and at pH 9.8 95827