Formation, cellular locations, isolation and enzymatic properties of PTP of Porphyromonas
gingivalis, an anaerobic periodontal pathogen were investigated. Almost all activities of this enzyme were detected in the de extract of the cell, but the other bacterial fractions such as culture fluids, envelopes and vesicles were not found to contain PTP. PTP was purified from the crude extract prepared by sonication and centrifugation through five steps including concentration, ion exchange hromatography, gel filtration, hydrophobic interaction chromatography and isoelectric focusing to homogeneity. The enzyme was a serine enzyme since it was inhibited strongly by Pefabloc SC, propyl
fluorophosphate and 3,4–dichloroisocoumarin. It hydrolyzed H–Ala–Ala–Pro–pNA and H–Ala–Phe–Pro–pNA. The molecular mass was determined as 45 kDa and isoelectric point was 5.₇. Optimum pH was moderately broad, and maximum activity was observed in the range of pH ₇.0 to 9.0. The residual activity after heating at 50℃ for 5 min was 29%, but heating at 60℃ resulted
in complete loss of the activity.
Formation, isolation and characterization of a prolyl tripeptidyl peptidase of Porphyromonas gingivalis
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