Researchers from the University of Florida and the University of Washington have identified the thousands of proteins Porphyromonas gingivalis produces, shedding light on how this bacterium interacts with healthy cells to thrive, according to an article in the January issue of the journal Proteomics.
Researchers have been trying to understand how P. gingivalis interacts with healthy oral tissues to cause disease. In the study, they used cutting-edge molecular research techniques to map all the proteins—known as the proteome—produced by P. gingivalis. Ultimately, they were able to fill hundreds of gaps in the organism’s sequence of roughly 2,000 proteins.
Researchers compared the proteins secreted by P. gingivalis when grown in a medium containing human gingival cell proteins with the proteins produced by the bacteria when grown in a neutral medium. Researchers separated bacterial proteins from the two conditions using a new technique called multidimensional protein identification technology.
Once the proteins were separated, researchers used mass spectrometry to measure each protein’s mass and charge—identifiers as unique to proteins as the whorls of fingerprints are to people. The spectrometry measurements were put into a computer database to create a computational model of the P. gingivalis proteome. Researchers found that the behavior, or protein expression, of the organism when it is at work in a human gingival environment is different from its behavior when it is in a neutral environment.
These results suggest that adaptation to an oral cavity environment induces a major shift in the expressed proteome of the organism said the researchers.
"This study is important in that we now have an understanding of the protein expression on a global scale for this pathogen," said study investigator Richard Lamont, Ph.D., a professor of oral biology at University of Florida’s College of Dentistry. "Now we need to see how it adapts to various situations present in the mouth to cause disease."
The next step will be to expose P. gingivalis to other oral pathogens to determine what interactions may exist that contribute to infection.
