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Multiple forms of the major phenylalanine specific protease in Treponema denticola
1Department of Oral Biology, Hebrew University, Hadassah, Faculty of Dental Medicine, Jerusalem, Israel. grosen@pob.huji.ac.il
Abstract:
The 160, 190 and 270 kDa outer sheath proteases of Treponema denticola ATCC 35404 were found to be multiple forms of the major 91 kDa phenylalanine protease (PAP) by immunoblotting using anti-91 kDa specific antibodies. Multiple forms of the phenylalanine protease were also found in 2 other T. denticola strains studied, ATCC 33520 and the clinical isolate GM-1. Protein, proteolytic and Western blot analyses using antibodies against the PAP and the major outer sheath protein (MSP) indicated that the 190 and 270 kDa proteases were protein complexes formed by the MSP and the PAP. These complexes dissociated by storage in 0.3% or higher SDS concentrations. The purified PAP was found to completely degrade keratin, but was unable to degrade native actin either in its monomeric or polymerized form. The association of the MSP adhesin with a protease capable of degrading host native proteins may benefit the obtention of protein-based nutrients necessary to support the growth of these treponemes. These complexes may also play a role in the structural organization of T. denticola outer sheath.
Insights
Treponema denticola outer sheath contains multiple forms of phenylalanine protease (PAP), some of which are complexes with the major outer sheath protein (MSP). These complexes degrade keratin, potentially aiding nutrient acquisition for the bacteria.
Area of Science:
- Microbiology
- Bacteriology
- Oral Microbiology
Background:
- Treponema denticola is a key pathogen in periodontal diseases.
- The outer sheath of T. denticola contains various proteins, including proteases and adhesins.
- Understanding the function of these proteins is crucial for elucidating virulence mechanisms.
Purpose of the Study:
- To characterize the outer sheath proteases of Treponema denticola.
- To investigate the relationship between the major outer sheath protein (MSP) and phenylalanine protease (PAP).
- To determine the substrate specificity and potential role of these proteases in bacterial nutrition and outer sheath structure.
Main Methods:
- Immunoblotting using specific antibodies against PAP and MSP.
- Protein and proteolytic analyses.
- Western blot analysis to identify protein complexes.
- Degradation assays using purified PAP on keratin and actin.
Main Results:
- Outer sheath proteases of T. denticola ATCC 35404, ATCC 33520, and GM-1 were identified as multiple forms of PAP.
- 190 and 270 kDa proteases were found to be complexes of MSP and PAP, dissociating in SDS.
- Purified PAP degraded keratin but not actin.
- The MSP-PAP complexes may facilitate nutrient acquisition and contribute to outer sheath structure.
Conclusions:
- The major 91 kDa phenylalanine protease (PAP) exists in multiple forms in T. denticola outer sheath.
- Complexes of MSP and PAP are identified and may play roles in nutrient acquisition and structural integrity.
- The substrate specificity of PAP suggests a role in host protein degradation for nutritional benefit.