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Porphyromonas gingivalis as a Model Organism for Assessing Interaction of Anaerobic Bacteria with Host Cells
Published on: December 17, 2015
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Porphyromonas gingivalis Gingipains Display Transpeptidation Activity.
Lianyi Zhang1, Paul D Veith1, N Laila Huq1
1Oral Health Cooperative Research Centre, Melbourne Dental School, Bio21 Institute , The University of Melbourne , Melbourne , Victoria , Australia.
Journal of Proteome Research
|July 10, 2018
Summary
Porphyromonas gingivalis proteases utilize peptide acceptors, like glycylglycine, to enhance hemoglobin digestion via transpeptidation over hydrolysis. This process may contribute to autoimmune disorders by modifying host proteins.
Area of Science:
- Microbiology
- Biochemistry
- Immunology
Background:
- Porphyromonas gingivalis is a key pathogen in periodontal disease.
- Its proteases, Lys-gingipain (Kgp) and Arg-gingipains (RgpA/RgpB), are crucial virulence factors.
- These proteases' activity is modulated by small peptides.
Purpose of the Study:
- To investigate the role of peptide acceptors in gingipain activity.
- To determine if gingipains catalyze transpeptidation reactions.
- To explore the in vivo relevance of gingipain-mediated transpeptidation.
Main Methods:
- Enzymatic digestion of human hemoglobin using purified gingipains and P. gingivalis whole cells.
- Analysis of digestion products with and without peptide acceptors (glycylglycine) using mass spectrometry.
- Comparison of transpeptidation versus hydrolysis activity.
Main Results:
- Glycylglycine promoted transpeptidation over hydrolysis by gingipains.
- Transpeptidation activity increased with glycylglycine concentration.
- Extensive transpeptidation of hemoglobin was observed, enhancing digestion and producing numerous products.
Conclusions:
- Gingipain-catalyzed transpeptidation is a significant reaction pathway.
- This process can modify host proteins like hemoglobin.
- Transpeptidation of host proteins in vivo may contribute to autoimmune reactions by disrupting immunological tolerance.
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