Is water essential to life?
25 May 2012 by Evoluted New Media
Contrary to popular belief, proteins are not dependant on water to survive and function say researchers from Bristol who have shown that myoglobin can refold in an environment almost completely devoid of water.
Researchers from the University of Bristol believe their findings could pave the way for the development of new industrial enzymes where hyperthermal resistance could play a role – applications such as biosensor development, and electrochemical reduction of CO2 to liquid fuels.
Proteins consist of one or more polypeptides – if heated in water to a temperature approaching boiling point, the highly organised 3D amino acid chains lose their structure and the protein will unfold or denature.
“This is part of the process that occurs when an egg is hard-boiled; the structures of the proteins in the egg unfold with temperature and stick together creating a solid,” said Dr Adam Perriman, lead researcher of the paper published in Chemical Science.
Since proteins evolved in a water-rich environment, it was thought that water was essential to the refolding process, but the findings of the Bristol team suggest this isn’t necessarily the case.
Using a spectroscopic technique called circular dichroism, the team – from the Department of Chemistry – showed that the oxygen-carrying protein myoglobin can refold in an environment that is almost completely devoid of water molecules.
“We achieved this by attaching polymer molecules to the surface of the protein and then removing the water to give a viscous liquid which, when cooled from a temperature as high as 155°C, refolded back to its original structure,” said Perriman
“Then we used the Circular Dichroism beamline (B23) at Diamond Light Source to track the refolding of the myoglobin structure and were astounded when we became aware of the extremely high thermal resistance of the new material.”
