Small gas molecules, such as O2, NO and CO, are used in many biological processes as signalling molecules, allowing living organisms to adapt to different environmental conditions by means of in built regulatory systems.   The gas molecules work as signalling molecules by interacting with 'sensor' metalloproteins

Professor Shigetoshi Aono, based at the National Institute of Natural Sciences, describes, in his Dalton Transactions Perspective article, how these gas molecules bind to the metal centre in the metalloproteins.   As the gas molecule binds to the metal, it triggers a conformational change in the protein.   These conformational changes can then be easily indentified using a range of conventional spectroscopic techniques.  

As Aono points out, however, there is still further research to be done in this area, to fully understand the relationship between the function of the metalloproteins and their structure.   'The determination of the structures for both the on- and off-states is a next important challenge for the research of the gas sensor proteins,' says Aono.