Dentilisin activity affects the organization of the outer sheath of Treponema denticola.
Prolyl-phenylalanine-specific serine protease (dentilisin) is a major extracellular protease produced by Treponema denticola. The gene, prtP, coding for the protease was recently cloned and sequenced (K. Ishihara, T. Miura, H. K. Kuramitsu, and K. Okuda, Infect. Immun. 64:5178-5186, 1996). In order to determine the role of this protease in the physiology and virulence of T. denticola, a dentilisin-deficient mutant, K1, was constructed following electroporation with a prtP-inactivated DNA fragment. No chymotrypsin-like protease activity was detected in the dentilisin-deficient mutant. In addition, the high-molecular-mass oligomeric protein characteristic of the outer sheath of the organism decreased in the mutant. Furthermore, the hydrophobicity of the mutant was decreased, and coaggregation of the mutant with Fusobacterium nucleatum was enhanced compared to that of the wild-type organism. The results obtained with a mouse abscess model system indicated that the virulence of the mutant was attenuated relative to that of the wild-type organism. These results suggest that dentilisin activity plays a major role in the structural organization of the outer sheath of T. denticola. The loss of dentilsin activity and the structural change in the outer sheath affect the pathogenicity of T. denticola.
Department of Microbiology, Oral Health Science Center, Tokyo Dental College, 1-2-2 Masago, Mihama-ku, Chiba 261-8502, Japan. ishihara@tdc.ac.jp
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Ishihara
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Kuramitsu
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Miura
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Okuda
D000818:Animals; D001426:Bacterial Proteins; D002462:Cell Membrane / Q000502:physiology / Q000648:ultrastructure*; D002918:Chymotrypsin / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D003001:Cloning, Molecular; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000235:genetics; D005673:Fusobacterium / Q000235:genetics; D015151:Immunoblotting; D051379:Mice; D010447:Peptide Hydrolases; D010508:Periodontal Abscess / Q000382:microbiology / Q000503:physiopathology; D010957:Plasmids; D016133:Polymerase Chain Reaction; D016966:Porphyromonas gingivalis / Q000235:genetics; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000302:isolation & purification / Q000378:metabolism; D014208:Treponema / Q000201:enzymology / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D014211:Treponemal Infections / Q000503:physiopathology; D014774:Virulence
D001426:Bacterial Proteins; D011994:Recombinant Proteins; D010447:Peptide Hydrolases; C102570:dentilisin; D002918:Chymotrypsin