Scientists have identified a new protein that helps an oral bacterium to survive various locations around the body. The discovery, based on around the way the bacterium adapts, could eventually lead to the development of new drugs that specifically target the protein.
The bacterium is named Fusobacterium nucleatum. This is a Gram-negative, anaerobic oral bacterium, commensal to the human oral cavity, that plays a role in periodontal disease (especially as a key component of periodontal plaque).
The bacterium is common in the mouths of humans and generally does not cause disease in that location. The organism presents a risk if it travels through the bloodstream to other areas of the body. Under disease conditions it is one of the most prevalent species found in extra-oral sites.
For example, the bacterium is prevalent in the tumours of colorectal cancer patients. The presence of the bacteria can contribute to tumour growth, spread of cancer to other sites in the body, and resistance to chemotherapy.
The researchers from the University of British Columbia (UBC) have determined that the new protein they identified enables the bacteria to take essential nutrients, such as iron, from our blood cells.
According to lead researcher Dr. Kirsten Wolthers: “Most of the iron in the body is tied up in a molecule called heme which is surrounded by a protein cage. What we’ve discovered now is a new way for this bacterium to acquire essential nutrients from a very abundant source allowing it to grow very well in parts of the body that are free of oxygen.”
Heme is also found in blood. The heme part of haemoglobin is the substance inside red blood cells that binds to oxygen in the lungs and carries it to the tissues.
The newly identified protein may prove to be a good target for drugs designed to attack this specific bacterium.
Wolthers states that much protein research relies on synchrotron technology. This enabled the research team to identify the distinct section of the protein that binds to the heme, helping the researchers to observe the part of the protein that is unique and interesting.
The synchrotron technology was provided by the Canadian Light Source (CLS), which is a national research facility of the University of Saskatchewan and it represents one of the largest science projects in Canada’s history.
The discovery then enabled the scientists to find a scaffold that could help with future drug design.
The research appears in the Journal of Biological Chemistry, titled “A new member of the flavodoxin-superfamily from Fusobacterium nucleatum that functions in heme-trafficking and reduction of anaerobilin.”
