Unknown haemoglobin function discovered

The discovery of a previously undetected chemical process within the oxygen-carrying molecule, haemoglobin, could have far-reaching implications for the treatment of cardiovascular diseases.

In a paper published online in the journal Nature Chemical Biology, research has shown how haemoglobin, through a catalytic reaction that does not change its own chemical properties, converts nitrite salt to the vasodilator nitric oxide.

The paper further documents how the nitric oxide activity harnessed by haemoglobin escapes the red blood cell to regulate blood flow and how the process, surprisingly, relies on the rusted form of haemoglobin, previously associated only with diseased states.

“We believe we have solved the paradox of how haemoglobin mediates the conversion of nitrite to nitric oxide in a way that it is not immediately destroyed in the red cell and so it can be effective biologically,” said senior author Daniel Kim-Shapiro, professor of physics at Wake Forest.

In 2003, the same team and their colleagues had discovered that nitrite salt, the same substance used to cure meat and previously thought to be biologically inert, serves in the cell as a storage pool for nitric oxide.

Since then, nitrite has been the object of intense study by researchers worldwide in pursuit of new treatments for such conditions as sickle cell disease, myocardial infarction, pulmonary hypertension, stroke and atherosclerosis.