Ice Cold: Cooler Than Being Cool

Nov 24, 2009
Alaskan beetle Upis ceramboides produces a nonprotein "antifreeze" molecule. Credit: Kent Walters, University of Notre Dame

(PhysOrg.com) -- Water expands when it freezes. Anyone who has ever left a can of soda or bottle of water in the freezer too long has witnessed this first hand. So how do plants and animals survive severe temperatures?

Insects exposed to subzero temperatures can adapt to the extreme climate to survive freezing temperatures, but until now, antifreeze molecules had not been isolated from freeze-tolerant animals. The NSF-supported study, published in the November 24 issue of , describes a brand new type of antifreeze molecule isolated from a freeze-tolerant Alaskan beetle by Kent Walters and colleagues at the University of Notre Dame.

Interestingly, the antifreeze molecule described by the research team differs from previously described factors in that it is not a protein, but a combination of saccharides and fatty acids, which are other types of biomolecules. What does that mean? Size is one big difference. The exact size of this particular molecule is unknown, but the fact that it is small could prove beneficial. The chemical composition of the molecule could prove amenable to commercial production because small chains of sugars can be readily synthesized in the laboratory, making them cheaper and easier to manufacture than biologically assembled molecules.

Antifreeze molecules are present in many organisms including fish, insects, plants, and bacteria. "The most active known antifreeze proteins had been described in freeze-avoiding insects, allowing certain insects to survive temperatures below -60 C (-76 F)" said Walters. However, this is the first reported isolation of antifreeze from a freeze-tolerant insect (those able to survive freezing).

One reason is that the antifreeze molecules are not always present. Dropping temperatures serve as a signal that the insects respond to by activating a host of adaptive responses including expression of antifreeze molecules. Researchers can artificially stimulate this response by conditioning the insects before they perform experiments.

Current methods used to cryopreserve tissues result in low viability after thaw, in part because existing solutes must be used at concentrations that are often toxic to cells or tissues. Because the new antifreeze molecule exhibits activity at relatively low concentrations in , it is possible researchers may be able to use them at low concentrations in the lab too.

According to Walters, "Potential applications for this new class of antifreeze molecules are abundant. In terms of cryopreservation, we may be able to increase viability and enhance survivorship of cells and tissues from other organisms under freezing conditions."

Provided by NSF

Explore further: Molecular gate that could keep cancer cells locked up

add to favorites email to friend print save as pdf

Related Stories

Antifreeze fish make sense out of junk DNA

Apr 04, 2006

Scientists at the University of Illinois have discovered an antifreeze-protein gene in cod that has evolved from non-coding or 'junk' DNA. Since the creation of these antifreeze proteins is directly driven by polar glaciation, ...

Recommended for you

Molecular gate that could keep cancer cells locked up

Jul 31, 2014

In a study published today in Genes & Development, Dr Christian Speck from the MRC Clinical Sciences Centre's DNA Replication group, in collaboration with Brookhaven National Laboratory (BNL), New York, ...

The 'memory' of starvation is in your genes

Jul 31, 2014

During the winter of 1944, the Nazis blocked food supplies to the western Netherlands, creating a period of widespread famine and devastation. The impact of starvation on expectant mothers produced one of the first known ...

Sugar mimics guide stem cells toward neural fate

Jul 30, 2014

Embryonic stem cells can develop into a multitude of cells types. Researchers would like to understand how to channel that development into the specific types of mature cells that make up the organs and other structures of ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Birger
not rated yet Jan 05, 2010
Also, see the Physorg.com article "Scientists isolate new antifreeze molecule in Alaska beetle". It would be interesting to learn more about the human toxicity (if any) of this anifreeze compound, and its ability to pass the blood-brain barrier.