Xylomannan is a newly discovered antifreeze molecule, found in the freeze-tolerant Alaskan beetle Upis ceramboides. Unlike antifreeze protein

Antifreeze protein

Antifreeze proteins or ice structuring proteins refer to a class of polypeptides produced by certain vertebrates, plants, fungi and bacteria that permit their survival in subzero environments. AFPs bind to small ice crystals to inhibit growth and recrystallization of ice that would otherwise be...

s, xylomannanis not a protein. Instead, it is a combination of a sugar (saccharide

Disaccharide

A disaccharide or biose is the carbohydrate formed when two monosaccharides undergo a condensation reaction which involves the elimination of a small molecule, such as water, from the functional groups only. Like monosaccharides, disaccharides form an aqueous solution when dissolved in water...

) and a fatty acid

Fatty acid

In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...

 that is found in cell membrane

Cell membrane

The cell membrane or plasma membrane is a biological membrane that separates the interior of all cells from the outside environment. The cell membrane is selectively permeable to ions and organic molecules and controls the movement of substances in and out of cells. It basically protects the cell...

s. As such is expected to work in a different manner than AFPs. It is believed to work by incorporating itself directly into the cell membrane and preventing the freezing of water molecules within the cell.

, it is unknown if xylomannan is found in other organisms, nor is it known exactly how it works.

External links

• New Antifreeze Molecule Isolated In Alaska Beetle - Science News - redOrbit
• [www.pnas.org/content/early/2009/11/20/0909872106.full.pdf ]