Characterization of proteinase–adhesin complexes of Porphyromonas gingivalis

Abstract

Proteinase-adhesin complexes of Porphyromonas gingivalis wild-type and RgpA and Kgp mutants were extracted using a Triton X-114 procedure and purified using arginine-affinity chromatography. The complexes were then characterized by peptide mass fingerprinting (PMF) and their equilibrium binding constants, immunogenicity and ability to induce protection as vaccines in the murine lesion model determined. The Triton X-114 procedure resulted in consistently higher yield and specific activity of the wild-type (wt) complex compared with that produced by the previously published sonication method. PMF and N-terminal sequencing of the purified wt complex showed that it consisted of the previously identified Arg-specific proteinase RgpA cat , the Lys-specific proteinase Kgp cat and adhesin domains RgpA A1 , RgpA A2 , RgpA A3 , Kgp A1 and Kgp A2 . However, analysis of the 30 kDa band in the wt complex, previously suggested to be RgpA A4 , indicated that this band contained C-terminally truncated Kgp A1 (which has an identical N-terminus to RgpA A4 ) as well as the HagA A1 * adhesin. Analysis of the Triton X-114 extracted complexes from the P. gingivalis isogenic mutants kgp (RgpA complex) and rgpA (Kgp complex) suggested that the Kgp complex consisted of Kgp cat , Kgp A1 and Kgp A2 /HagA A2 and that the RgpA complex consisted of RgpA cat , RgpA A1 , HagA A1 *, RgpA A2 and RgpA A3 . Each of the complexes was found to have equilibrium binding constants (K D ) in the nanomolar range for fibrinogen, fibronectin, haemoglobin, collagen type V and laminin. However, the Triton-wt complex exhibited significantly lower K D values for binding to each host protein compared with the sonication-wt complex, or the Triton-RgpA complex and Triton-Kgp complex. Furthermore, the Triton-wt complex induced a stronger antibody response to the A1 adhesins and tended to be more effective in providing protection in the mouse lesion model compared with the sonication-wt complex.

The RgpA-Kgp Proteinase-Adhesin Complexes ofPorphyromonas gingivalisInactivate the Th2 Cytokines Interleukin-4 and Interleukin-5

“…P. gingivalis strain W50 cells were grown as previously described (20), and the RgpA-Kgp complexes were isolated, purified, and analyzed as described by Pathirana et al (25).…”

Macrophage Depletion Abates Porphyromonas gingivalis–Induced Alveolar Bone Resorption in Mice

“…The protein extraction and purification of the RgpA-Kgp complexes (from strain W50) were described by Pathirana et al (72). To prepare heat-killed P. gingivalis W50 (HK-W50), P. gingivalis W50 culture was harvested, washed once with PBS, and pelleted by centrifugation, as described (69)(70)(71).…”

Porphyromonas gingivalis-derived RgpA-Kgp Complex Activates the Macrophage Urokinase Plasminogen Activator System

“…The purification of the RgpA-Kgp complexes was performed as before (35) and were activated prior to use with 10 mM L-cysteine in 0.5 M Tris/HCl, pH 7.4 buffer.…”