title: Studies on the aminopeptidase activities of Porphyromonas gingivalis.
abstract: Porphyromonas gingivalis is an asaccharolytic bacterium that requires nitrogen substrates as carbon and energy sources. The aims of this study were to investigate the aminopeptidase activities of P. gingivalis and to evaluate the effect of aminopeptidase inhibitors on bacterial growth. Only arginine aminopeptidase and dipeptidyl aminopeptidase IV activities were detected. Experimental evidence was obtained suggesting that the Arg-gingipains of P. gingivalis can function as both an endopeptidase and an aminopeptidase. Firstly, the arginine aminopeptidase activity was found to be inhibited by leupeptin, a well-known inhibitor of Arg-gingipain activity. Secondly, a preparation of Arg-gingipain activity could hydrolyze the chromogenic substrate for arginine aminopeptidase. Lastly, a mutant of P. gingivalis constructed via gene disruption by use of suicide plasmids and deficient in both Arg-gingipain A and B was also devoid of arginine aminopeptidase activity. To investigate the key role of aminopeptidase activities in growth of P. gingivalis, aminopeptidase inhibitors were incorporated in the culture medium prior to inoculation. Bestatin and actinonin were the only ones to inhibit growth of P. gingivalis. Their mechanism of growth inhibition appears to be different but does not involve inhibition of the two major aminopeptidase activities (arginine aminopeptidase and dipeptidyl aminopeptidase IV).
authors.affiliation: Groupe de Recherche en Ecologie Buccale, Faculté de Médecine Dentaire and Faculté des Sciences et de Génie, Université Laval, Québec, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Grenier
authors.forename: P
authors.initials: P
authors.lastname: Gauthier
authors.forename: P
authors.initials: P
authors.lastname: Plamondon
authors.forename: K
authors.initials: K
authors.lastname: Nakayama
authors.forename: D
authors.initials: D
authors.lastname: Mayrand
mesh_terms: D018829:Adhesins, Bacterial / Q000032:analysis / Q000235:genetics; D000626:Aminopeptidases / Q000032:analysis* / Q000037:antagonists & inhibitors / Q000235:genetics; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002250:Carbon Radioisotopes; D002403:Cathepsins / Q000037:antagonists & inhibitors; D002863:Chromogenic Compounds; D003546:Cysteine Endopeptidases / Q000032:analysis / Q000235:genetics; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D018819:Dipeptidyl Peptidase 4 / Q000032:analysis; D000080867:Gingipain Cysteine Endopeptidases; D006146:Guanidines / Q000494:pharmacology; D006388:Hemagglutinins / Q000032:analysis / Q000235:genetics; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology; D007930:Leucine / Q000031:analogs & derivatives / Q000494:pharmacology; D007976:Leupeptins / Q000494:pharmacology; D009154:Mutation / Q000235:genetics; D009842:Oligopeptides / Q000494:pharmacology; D010455:Peptides; D016966:Porphyromonas gingivalis / Q000187:drug effects / Q000201:enzymology* / Q000254:growth & development; D011480:Protease Inhibitors / Q000494:pharmacology; D019275:Radiopharmaceuticals
chemical_list: D018829:Adhesins, Bacterial; D000900:Anti-Bacterial Agents; D002250:Carbon Radioisotopes; D002863:Chromogenic Compounds; D015853:Cysteine Proteinase Inhibitors; D000080867:Gingipain Cysteine Endopeptidases; D006146:Guanidines; D006388:Hemagglutinins; D006877:Hydroxamic Acids; D007976:Leupeptins; D009842:Oligopeptides; D010455:Peptides; D011480:Protease Inhibitors; D019275:Radiopharmaceuticals; C016977:amastatin; C040038:arphamenine A; C041445:diprotin A; D002403:Cathepsins; D000626:Aminopeptidases; C019721:aminopeptidase B; D018819:Dipeptidyl Peptidase 4; D003546:Cysteine Endopeptidases; D007930:Leucine; C012211:ubenimex; C032854:leupeptin; C010531:actinonin