Figure 1
From: Prolyl oligopeptidase is inhibited in relapsing-remitting multiple sclerosis
Prolyl oligopeptidase activity is sensitive to chelating agents but the alternative ZIP activity is not. Prolyl endopeptidase activity in plasma from healthy controls collected in the presence of citrate (gray bars) or EDTA (white bars). A. Z-Pro-Prolinal insensitive prolyl endopeptidase (ZIP). B. POP activity, *, p-value = 0.037. n = 4. C. Effect of increasing concentrations of citrate (-▲-) or EDTA (-■-) on human recombinant purified POP activity. Concentrations of 1.8 mg/ml EDTA or 3.2 mg/ml citrate (arrows) were used in the experiments shown in A. and B.