Scientists watch water help proteins fold

CHAMPAIGN, Ill., Aug. 7 (UPI) -- Once believed unique to Earth, water has been found in comets, Mars and space -- and now U.S. scientists find it isn't really quite what they thought it was.

"Water in our bodies has different physical properties from ordinary bulk water, because of the presence of proteins and other biomolecules," said University of Illinois Professor Martin Gruebele.

When bound with water molecules, proteins fold into their functional, native states in a process essential for life.

Using a technique called terahertz absorption spectroscopy, Gruebele and Professor Martina Havenith at Ruhr University Bochum in Germany studied the motions of a folding protein and water molecules on a picosecond timescale.

"This is the first time we've been able to look at the motion of water molecules during the folding process," said Gruebele. "We previously thought proteins would affect only those water molecules directly stuck to them. Now we know proteins will affect a volume of water comparable to their own. That's pretty amazing."

The research, which included graduate students Seung Joong Kim and Benjamin Born, appeared in the July 23 online version of the journal Angewandte Chemie.