Arylaminopeptidase Activities of Oral Bacteria

Abstract

Protease and peptidase enzymes are thought to play a role in the virulence of many oral organisms, especially those associated with periodontal diseases. In order to evaluate the peptidases of periodontopathogens, we compared the arylaminopeptidase activities of Bacteroides gingivalis with those of other oral and non-oral bacteria. Sixty-three bacterial strains representing the prominent cultivable organisms in human periodontal pockets were tested, including representatives of the black-pigmented Bacteroides, Actinobacillus, Actinomyces, Campylobacter, Capnocytophaga, Eikenella, Fusobacterium, Haemophilus, Lactobacillus, Streptococcus, and Veillonella species. Each micro-organism was examined for its ability to hydrolyze 18 synthetic substrates of beta-naphthylamide derivatives of amino acids, dipeptides, and tripeptides. Quantitation of the enzyme activity was accomplished by colorimetric measurement of the amounts of released beta-naphthylamines. N-CBz-glycyl-glycyl-L-arginine-beta-naphthylamide was readily cleaved by B. gingivalis, but slightly or not at all by the other oral strains tested. L-arginine-beta-naphthylamide was cleaved by B. gingivalis, Capnocytophaga species, and Streptococcus species, but not readily by the other Bacteroides strains. Some dipeptide substrates tested, such as glycyl-L-arginine- and glycyl-L-proline-beta-naphthylamide, were strongly cleaved by B. gingivalis and weakly cleaved by other Bacteroides strains. Since high levels of N-CBz-glycyl-glycyl-L-arginyl-aminopeptidase activity are characteristic of B. gingivalis, its measurement may be valuable in the identification of this organism in clinical samples as an aid in diagnosis and monitoring of periodontal infections. Furthermore, this and other aminopeptidases produced by B. gingivalis and other oral organisms may play a role in the tissue destruction seen in periodontal disease.

Identification of Periodontopathic Bacteria Based Upon their Peptidase Activities

“…B. gingivalis was the only organism to cleave N-CBz-Gly-Gly-Argp-NA among black-pigmented Bacteroides strains tested (Nakamura et ah, 1984;Suido et aL, 1986). The present study showed similar results.…”

“…Peptidase activities were measured following the methods previously reported by Suido et al (1986) with some modifications. Reaction mixtures were prepared with 20 jxL of 1 mmol/L substrate, 80 |xL of 0.1 mol/L Tris-HCl buffer (pH 7.5), and 20 |xL of distilled water per well of a microtiter plate.…”

“…B. gingivalis and T. denticola have been reported to possess a trypsin-like enzyme (Slots, 1981;Laughon et al, 1982a,b). Particularly, B. gingivalis was found to produce strong NCBz-Gly-Gly-Arg-P-NA-hydrolyzing activity, which was not found in a large number of other organisms (Suido et al, 1986). It has been shown, also, that blackpigmented Bacteroides and other oral bacteria have some arylaminopeptidase activities (Nakamura and Slots, 1982;Suido et al, 1986).…”

Identification and Characterization of Prokaryotic Dipeptidyl-peptidase 5 from Porphyromonas gingivalis

“…Gly-Pro-MCA by DPP4; LysAla-MCA by both DPP7 and DPP4; Met-Leu-, Gly-Phe-, LeuArg-, and Ser-Tyr-MCA by DPP7; and Leu-Asp-, Leu-Glu-, and Val-Asp-MCA by DPP11, whereas Leu-Gln-MCA may be cleaved by DPP7 because of its hydrophobic P2 preference (33). Several substrates such as Thr-Ser-and Gly-Gly-MCA were scarcely released by the bacterium, as suspected based on the substrate preferences of the 3 DPPs and a previous report that noted that no peptidase was found to be responsible for Thr, Ser, and Gly in P. gingivalis (34). Thr-Asp-and His-Asp-MCA were also scarcely hydrolyzed, because DPP11 prefers a hydrophobic P2 residue (24).…”

Bacterial Colonization and Degradation of Demineralized Dentin Matrix in situ

“…dentin specimens similar to those used in this study were incubated with trypsin at 37°C which resulted in a collagen loss of 70% within 24 h. Nonspecific proteolytic enzymes are pro duced by several bacterial species. Ova et al [1971], Andersson et al [1984] and Suido et al [1986] found aminopeptidase activity, which may be involved in the degrada tion of the organic matrix, in lactobacilli and strains of S. mitis and Streptococcus sanguis. Larmas et al [1986] found histochemical evidence for the occurrence of aminopeptidases in human carious dentin, which were of mi crobial origin [Larmas and Mäkinen.…”