Carbon monoxide is often called the "silent killer" because it is odorless and invisible, allowing it to enter the body unnoticed. CO accumulates in poorly ventilated spaces, leaks through faulty gas heaters, or is emitted when natural gas and propane are burned, such as on stoves. It is also a major component of smoke from fires. When it enters the bloodstream, CO binds to red blood cells, blocking oxygen delivery to the brain, heart, and other organs. CO binds to hemoglobin 200-400 times more effectively than oxygen, which can lead to loss of consciousness and irreversible damage within minutes.
Each year in the United States, approximately 50,000 people seek emergency care due to CO poisoning, and approximately 1,500 cases are fatal. Treatment is a race against time, as the trapped CO must be quickly removed from the blood. Currently, the only available treatment for those who reach the hospital in time is oxygenation, often using a hyperbaric chamber. This process is slow: removing CO from the blood can take an hour or more. If the patient survives, there is a risk of serious heart or brain damage.
The new therapy is based on the RcoM protein, found in the bacterium Paraburkholderia xenovorans. In nature, it reacts to trace amounts of CO in the environment. Researchers modified it to remove CO from human blood. The protein selectively binds to carbon monoxide, sparing oxygen (O₂) and nitric oxide (NO), which regulate blood pressure in the body.
Experiments in mice showed that the drug, called RcoM-HBD-CCC, removes CO from the blood in minutes. Half of the carbon monoxide molecules were removed in less than a minute, allowing hemoglobin to resume carrying oxygen.
Other protein-based drugs bind not only to CO but also to vital NO, causing vasoconstriction and increased blood pressure. RcoM-HBD-CCC selectively absorbs only carbon monoxide and has virtually no effect on the body. This makes it a promising rapid antidote that can be administered both in the hospital and in the field.
Although the research is still in the preclinical stage, scientists see enormous potential. In addition to treating carbon monoxide poisoning, RcoM-HBD-CCC may find application in severe anemia or hemorrhagic shock.
