Enzymatic Properties of Dipeptidyl Aminopeptidase IV Produced by the Periodontal PathogenPorphyromonas gingivalisand Its Participation in Virulence

Abstract

Porphyromonas gingivalis is a major pathogen associated with adult periodontitis. We cloned and sequenced the gene (dpp) coding for dipeptidyl aminopeptidase IV (DPPIV) from P. gingivalis W83, based on the amino acid sequences of peptide fragments derived from purified DPPIV. An Escherichia coli strain overproducing P. gingivalis DPPIV was constructed. The enzymatic properties of recombinant DPPIV purified from the overproducer were similar to those of DPPIV isolated from P. gingivalis. The three amino acid residues Ser, Asp, and His, which are thought to form a catalytic triad in the C-terminal catalytic domain of eukaryotic DPPIV, are conserved in P. gingivalis DPPIV. When each of the corresponding residues of the enzyme was substituted with Ala by site-directed mutagenesis, DPPIV activity significantly decreased, suggesting that these three residues of P. gingivalis DPPIV are involved in the catalytic reaction. DPPIV-deficient mutants of P. gingivalis were constructed and subjected to animal experiments. Mice injected with the wild-type strain developed abscesses to a greater extent and died more frequently than those challenged with mutant strains. Mice injected with the mutants exhibited faster recovery from the infection, as assessed by weight gain and the rate of lesion healing. This decreased virulence of mutants compared with the parent strain suggests that DPPIV is a potential virulence factor of P. gingivalis and may play important roles in the pathogenesis of adult periodontitis induced by the organism.

Degradation of Incretins and Modulation of Blood Glucose Levels by Periodontopathic Bacterial Dipeptidyl Peptidase 4

“…Furthermore, similar masses between recombinant and native DPP4 suggested that major posttranslational modifications did not occur in bacterial entities. Indistinguishable activities between native and recombinant PgDPP4s were reported previously (18,32). In addition, molecular masses of recombinant and native forms of DPP4 were estimated as approximately 9% smaller than those of the deduced sequences.…”

“…These similarities between PgDPP4 and hDPP4 led us to speculate that PgDPP4 mimics the role of hDPP4 in glycemic control during recurrent bacteremia in periodontal patients, which may explain the link between severe periodontitis and diabetes mellitus. Previous studies have shown that PgDPP4 hydrolyzes substance P, IL-1␤, IL-2 (18), RANTES, and monocyte chemoattractant protein 1 (MCP1) (32). However, whether PgDPP4 degrades incretins and other bioactive peptides in vivo, thereafter causing a pathological response, has yet to be elucidated.…”

Identification ofRiemerella anatipestifergenes differentially expressed in infected duck livers by the selective capture of transcribed sequences technique

“…DPP IV is a serine protease that cleaves X-Pro or X-Ala dipeptide from the N-terminal ends of polypeptide chains. DPP IV is an important virulence factor of Porphyomonas gingivalis by contributing to the degradation of connective tissues, and also mediates the adhesion of P. gingivalis to fibronectin (Kumagai et al, 2000(Kumagai et al, , 2005. The proteolysis of substance P by Sg-xPDPP was observed, and the concerted action of an extracellular Arg aminopeptidase and Sg-xPDPP produces a truncated form of bradykinin.…”

Peptidase Activity of Dipeptidyl Aminopeptidase IV Produced by Porphyromonas gingivalis Is Important but Not Sufficient for Virulence

“…The amino acid residues in the region associated with the peptidase activity have been reported in mouse DPPIV (6) and P. gingivalis DPPIV (12). The substitution of serine residue (Ser) 593 with alanine (Ala) in P. gingivalis DPPIV resulted in no detection of peptidase activity (12). The peptidase activity of eukaryotic DPPIV has been considered to be important for several biological and pathological functions of DPPIV.…”

“…through infection of mice with W83 or 4351 (12). Histopathological analysis has revealed that P. gingivalis DPPIV is involved in the destruction of connective tissue and the inhibition of inflammatory cell mobilization (28).…”