Water, water everywhere—but is it essential to life?

April 13, 2012

Proteins are large organic molecules that are vital to every living thing, allowing us to convert food into energy, supply oxygen to our blood and muscles, and drive our immune systems. Since proteins evolved in a water-rich environment, it is generally thought that they are dependent on water to survive and function.

Proteins consist of one or more polypeptides – chains of amino acids held together by peptide bonds. If a in water is heated to temperatures approaching the boiling point of water, these chains will lose their structure and the protein will denature (unfold).

A classic example of denaturing occurs when an egg is hard-boiled: the structures of the proteins in the egg unfold with temperature and stick together creating a solid. In the egg's case, this process cannot be reversed – however there are many examples where cooling the protein results in refolding of the structure.

Previously, it was thought that water was essential to the refolding process, however the Bristol findings suggest this isn't necessarily the case.

Using a spectroscopic technique called circular dichroism, Dr Adam Perriman of Bristol's School of Chemistry and colleagues have shown that the oxygen-carrying protein myoglobin can refold in an environment that is almost completely devoid of water molecules.

Dr Perriman said: "We achieved this by attaching polymer molecules to the surface of the protein and then removing the to give a viscous liquid which, when cooled from a temperature as high as 155°C, refolded back to its original structure.

"We then used the Circular Dichroism beamline (B23) at Diamond Light Source, the UK's national synchrotron science facility in Oxfordshire, 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."

These findings could pave the way for the development of new industrial enzymes where hyper-thermal resistance would play a crucial role, in applications ranging from biosensor development to electrochemical reduction of CO2 to liquid fuels.

Explore further: Engineers squeeze secrets from proteins

More information: 'Hyper-thermal stability and unprecedented re-folding of solvent-free liquid myoglobin' by Alex Brogan, Giuliano Siligardi, Rohanah Hussain, Adam Perriman and Stephen Mann in Chemical Science DOI: 10.1039/C2SC20143G

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5 / 5 (1) Apr 13, 2012
Water, water everywhere "& ndash" but is it essential to life?

You guys... really don't do even the most minor kind of checking, do you?
1 / 5 (4) Apr 14, 2012
Since proteins evolved in a water-rich environment,
I should point out that this is a nonsensical, pseudo science statement. The researcher or author of the article has zero supporting evidence that this was the case. Since proteins are essential for life they could not have "evolved". They had to be present already at the start of life. According to the evolutionary theory there can be no natural selection or mutations until life actually exists. Hence: this statement is just plain nonsense.
not rated yet Apr 14, 2012
Proteins are essential for life?

I think we should find some alternate life before we go deciding such things.

5 / 5 (3) Apr 14, 2012
The researcher or author of the article has zero supporting evidence that this was the case -KevinTard

What do you care about evidence? Your god delusion doesn't require it, so why are you asking for it?
not rated yet Apr 14, 2012
Water, water everywhere "& ndash" but is it essential to life?

You guys... really don't do even the most minor kind of checking, do you?

phys.org is probably just a bot that scrapes content from other sites
4 / 5 (1) Apr 14, 2012
I'm afraid I'll have to add a frown to those already expressed about this article.

The headline poses a question, but the article makes no attempt to answer it. The research cited does not answer it, either.

Nor could it. Looking at a specific group of proteins under specific conditions doesn't even scratch the surface of a question as big as "is water essential to life?"

This summary, bluntly, is guilty of hyperbole. I don't know if the paper cited is also guilty of it.
not rated yet Apr 14, 2012
Water may not be required, but chemical life will require a solvent and there are a limited number of those to be found in space, and they are limited to specific temperatures and pressures.

As a practical matter there is only one practical solvent. Water.

Liquid methane probably comes next, but given it's temperature, I don't expect to find enough thermal energy to produce life.

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