Could cyanobacterial proteins hold the key to the 'hydrogen economy'?
Could cyanobacterial proteins hold the key to the ’hydrogen economy’?
A crystal structure recently published in Science by a team at Imperial College London, UK, (Chemistry World, March 2004, p10) has led Gary Brudvig and James McEvoy at Yale University, US, to speculate on the mechanistic functions of calcium and chlorine in the oxygen-evolving complex (OEC) of a cyanobacterial photosystem II protein.
Photosystem II uses sunlight to split water into oxygen, electrons and protons; a process difficult to achieve non-biologically. By studying the OEC, Brudvig and McEvoy hope to design other biological systems and small-molecule mimics to convert efficiently water and sunlight into oxygen and hydrogen gas.
’One hears a lot about the forthcoming "hydrogen economy",’ says Brudvig, ’but all those fuel cells are going to need an abundant, renewable and clean source of hydrogen.’ The challenge now is to determine how each subunit and cofactor plays its part. ’Photosystem II is an enormous protein,’ he adds. ’So it’s going to take a long time.’
J P McEvoy and G W Brudvig, Phys. Chem. Chem. Phys., 2004 (DOI: 1039/ <MAN>b407500e</MAN>)