London, May 17 : Scientists at the German Cancer Research Center have identified a molecule, the level of which in a cell may reveal the "oxidative stress" status of the cell.
The finding attains significance because the right balance between oxidation and the reverse reaction called reduction makes the difference between health and disease, and this is the first study to show the possibility of measuring the level of oxidation.
Lead researcher Dr. Tobias Dick has revealed that the stress biosensor developed by his team measures the oxidation state of glutathione, an important protection molecule that captures a large portion of reactive oxygen molecules within a cell by oxidation.
He says that where much of a cells' glutathione is present in an oxidized state, it will be an important indicator of the cell's overall oxidation level.
His team equipped test cells with a fluorescent protein that reacts to changes in oxidation level by releasing light signals.
Since the fluorescent protein on its own is not sensitive enough, it was coupled with an enzyme called glutaredoxin, which "measures" the oxidation state of glutathione and transmits the value to the fluorescent protein.
Dick found that his stress biosensor could measure the slightest changes in the oxidation state of glutathione without destroying the cell.
He said that what was even more relevant was its precise time resolution.
"In order to measure short-term variations of oxidation state, the systems needs to react instantly and dynamically. This is guaranteed with our biosensor, which works down to the scale of seconds," Nature Methods quoted Dick as saying.
The measuring system allows researchers to determine those short-term variations that occur when reactive oxygen compounds are released as signalling molecules.
However, the biosensor is equally suitable for use in pharmaceutical research, as it may help determine the effect of new substances or plant food constituents on oxidative processes and, thus, on the stress status of cells.