Purification and Characterization of a Novel Cysteine Proteinase (Periodontain) from Porphyromonas gingivalis

Abstract

Periodontal disease is characterized by inflammation of the periodontium manifested by recruitment of neutrophils, which can degranulate, releasing powerful proteinases responsible for destruction of connective tissues, and eventual loss of tooth attachment. Although the presence of host proteinase inhibitors (serpins) should minimize tissue damage by endogenous proteinases, this is not seen clinically, and it has been speculated that proteolytic inactivation of serpins may contribute to progression of the disease. A major pathogen associated with periodontal disease is the Gram-negative anaerobe Porphyromonas gingivalis, and in this report, we describe a novel proteinase that has been isolated from culture supernatants of this organism that is capable of inactivating the human serpin, ␣ 1 -proteinase inhibitor, the primary endogenous regulator of human neutrophil elastase. This new enzyme, referred to as periodontain, belongs to the cysteine proteinase family based on inhibition studies and exists as a 75-kDa heterodimer. Furthermore, periodontain shares significant homology to streptopain, a proteinase from Streptococcus pyogenes, and prtT, a putative proteinase from P. gingivalis. Clearly, the presence of this enzyme, which rapidly inactivates ␣ 1 -proteinase inhibitor, could result in elevated levels of human neutrophil elastase clinically detected in periodontal disease and should be considered as a potential virulence factor for P. gingivalis.

Proteolysis of Human Monocyte CD14 by Cysteine Proteinases (Gingipains) fromPorphyromonas gingivalisLeading to Lipopolysaccharide Hyporesponsiveness

“…It is also possible that P. gingivalis and other infective organisms may elaborate proteinases that have similar functions to gingipains. In fact, a new cysteine proteinase from P. gingivalis referred to as periodontain was recently described (52). By using this mechanism, P. gingivalis may cause chronic inflammation by surviving in the periodontium.…”

Molecular Diversity of a Putative Virulence Factor: Purification and Characterization of Isoforms of an Extracellular Serine Glutamyl Endopeptidase of Enterococcus faecalis with Different Enzymatic Activities

“…Examples include the V8 proteinase of Staphylococcus aureus involved in septicemia (2,14,44) and its homologue GluSE from S. epidermidis, found to be important for slime production and, consequently, biofilm formation by this bacterium in vitro (36,43). Furthermore, the cysteine endopeptidase SpeB of Streptococcus pyogenes (8,9,16,(29)(30)(31) and proteases of Porphyromonas gingivalis (3,4,24,42,45), Yersinia spp. (22,28,(54)(55)(56), and Pseudomonas aeruginosa (10,17,23) have all been implicated as virulence factors.…”

Emerging Family of Proline-Specific Peptidases of Porphyromonas gingivalis : Purification and Characterization of Serine Dipeptidyl Peptidase, a Structural and Functional Homologue of Mammalian Prolyl Dipeptidyl Peptidase IV

“…These enzymes contribute significantly to the development and maintenance of pathological processes within the infected periodontal pocket through their ability to (i) activate the kallikreinkinin system (22), (ii) release neutrophil chemotactic activity from the native and oxidized C5 component of complement pathway (14), (iii) activate factor X, protein C, and prothrombin (21,23), (iv) process or degrade cytokines, including interleukin 6 (IL-6) (4, 15), IL-8 (32,42), gamma interferon (41), and tumor necrosis factor alpha (10), (v) degrade fibrinogen and some plasma proteins (37), (vi) activate neutrophils through cleavage of proteinase-activated receptor 2 (28), and (vii) cleave and inactivate the C5a receptor on phagocytes (25). The other group of P. gingivalis cysteine proteinases comprise the prtT gene product (30) and periodontain, a recently purified enzyme with the ability to cleave and inactivate ␣ 1 -proteinase inhibitor (33). Another gene, tpr, coding for a papainlike proteinase, has also been cloned, sequenced and expressed in Escherichia coli (8).…”