The scientists have been trying to understand how P. gingivalis interacts with healthy oral tissues to cause such devastation. In this study, they used cutting-edge molecular research techniques to map all the proteins ?known as the proteome ?produced by P. gingivalis. Ultimately, the researchers were able to fill hundreds of gaps in the organism’s sequence of roughly 2,000 proteins.
“The approach used in this study is very exciting,?said Hansel Fletcher, Ph.D., an associate professor of microbiology and molecular genetics at Loma Linda University in Loma Linda, Calif. “For the first time, we are able to see that the more than 200 so-called ‘hypothetical?proteins in P. gingivalis are expressed and have specific functions.?/p>
Until now, scientists had identified less than 2 percent of the pathogen’s proteins and had to guess at what other proteins might be present in the proteome based on similarities to other known proteins, said Fletcher.
“This study has done two things to advance that,?Lamont said. “We’ve identified the complete protein complement of the organism, and we’ve looked at how those proteins are expressed when the organism is in an environment that closely mimics an oral situation.?/p>
To do this, Lamont and his colleagues compared the proteins secreted by P. gingivalis when grown in a medium containing human gum cell proteins with the proteins produced by the bacteria when grown in a neutral medium. Bacterial proteins from the two conditions were separated using a new technique called Multidimensional Protein Identification Technology, or MudPIT.
Once separated, mass spectrometry was used 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 fed into a computer database to create a computational model of the P. gingivalis proteome, resul
Source:University Of Florida Health Science Center