title: Participation of the secreted dipeptidyl and tripeptidyl aminopeptidases in asaccharolytic growth of Porphyromonas gingivalis.
abstract: OBJECTIVE
  Porphyromonas gingivalis secretes gingipains, endopeptidases essential for the asaccharolytic growth of this bacterium. P. gingivalis also secretes dipeptidyl aminopeptidases (DPPIV and DPP-7) and a tripeptidyl aminopeptidase (PTP-A), although their role in asaccharolytic growth is unclear. The present study was carried out to elucidate the role of these dipeptidyl/tripeptidyl aminopeptidases on the asaccharolytic growth of P. gingivalis.
  
  
  METHODS
  Knockout mutants for the DPPIV (dpp), dpp7 and/or PTP-A genes were constructed. Brain-heart infusion medium supplemented with sterile hemin and menadione (BHIHM) was used as a complex medium, and the minimal medium used was GA, in which the sole energy source was a mixture of immunoglobulin G and bovine serum albumin. Growth of P. gingivalis was monitored by measuring the optical density of the culture.
  
  
  RESULTS
  All knockout mutants for DPPIV, dpp7 and PTP-A grew as well as strain W83 in BHIHM. In GA, growth of single-knockout and double-knockout mutants was similar to that of W83, whereas growth of a triple-knockout mutant (83-47A) was reduced. We purified recombinant DPPIV and recombinant PTP-A from recombinant Escherichia coli overproducers, and purified DPP-7 from the triple-knockout mutant 83-4A. GA supplemented with the three purified dipeptidyl/tripeptidyl aminopeptidases supported the growth of 83-47A.
  
  
  CONCLUSIONS
  DPPIV, DPP-7 and PTP-A contribute to the normal growth of P. gingivalis by cleaving substrate peptides into short-chain polypeptides that are efficient energy sources for P. gingivalis.
authors.affiliation: Department of Periodontology, Nippon Dental University School of Life at Tokyo, Tokyo, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Oda
authors.forename: K
authors.initials: K
authors.lastname: Saiki
authors.forename: M
authors.initials: M
authors.lastname: Tonosaki
authors.forename: A
authors.initials: A
authors.lastname: Yajima
authors.forename: K
authors.initials: K
authors.lastname: Konishi
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D000626:Aminopeptidases; D000818:Animals; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D002417:Cattle; D003470:Culture Media; D003546:Cysteine Endopeptidases / Q000378:metabolism; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases / Q000235:genetics / Q000378:metabolism*; D010450:Endopeptidases / Q000235:genetics / Q000378:metabolism*; D055786:Gene Knockout Techniques; D000080867:Gingipain Cysteine Endopeptidases; D006427:Hemin; D007074:Immunoglobulin G; D009154:Mutation; D010455:Peptides / Q000378:metabolism; D016966:Porphyromonas gingivalis / Q000201:enzymology / Q000254:growth & development*; D011994:Recombinant Proteins / Q000378:metabolism; D012710:Serum Albumin, Bovine; D024483:Vitamin K 3
chemical_list: D018829:Adhesins, Bacterial; D001426:Bacterial Proteins; D003470:Culture Media; D000080867:Gingipain Cysteine Endopeptidases; D007074:Immunoglobulin G; D010455:Peptides; D011994:Recombinant Proteins; D012710:Serum Albumin, Bovine; D024483:Vitamin K 3; D006427:Hemin; D010450:Endopeptidases; D000626:Aminopeptidases; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D003546:Cysteine Endopeptidases