Xylomannan is an antifreeze molecule, found in the freeze-tolerant Alaskan beetle ''

Upis ceramboides ''Upis ceramboides'' is a species of beetle, one of many wood-living insects that benefit from forest fires. It often occurs in quantities below the bark on the fire-damaged birches, but can sometimes be seen on other deciduous trees such as wil ...

''. Unlike

antifreeze protein Antifreeze proteins (AFPs) or ice structuring proteins refer to a class of polypeptides produced by certain animals, plants, fungi and bacteria that permit their survival in temperatures below the freezing point of water. AFPs bind to small ...

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

saccharide In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or ma ...

) and a

fatty acid In chemistry, particularly in biochemistry, a fatty acid is a carboxylic acid with an aliphatic chain, which is either saturated or unsaturated. Most naturally occurring fatty acids have an unbranched chain of an even number of carbon atoms, ...

that is found in

cell membrane The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment ( ...

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. Xylomannan is also found in the red seaweed '' Nothogenia fastigiata'' ( Scinaiaceae family). Fraction F6 of a sulphated xylomannan from ''Nothogenia fastigiata'' was found to inhibit replication of a variety of viruses, including Herpes simplex virus types 1 and 2 (HSV-1, HSV-2),

Human cytomegalovirus ''Human betaherpesvirus 5'', also called human cytomegalovirus (HCMV), is species of virus in the genus '' Cytomegalovirus'', which in turn is a member of the viral family known as ''Herpesviridae'' or herpesviruses. It is also commonly calle ...

(HCMV, HHV-5),

Respiratory syncytial virus Respiratory syncytial virus (RSV), also called human respiratory syncytial virus (hRSV) and human orthopneumovirus, is a common, contagious virus that causes infections of the respiratory tract. It is a negative-sense, single-stranded RNA virus. ...

(RSV),

Influenzavirus A '' A virus'' (''IAV'') causes influenza in birds and some mammals, and is the only species of the genus ''Alphainfluenzavirus'' of the virus family ''Orthomyxoviridae''. Strains of all subtypes of influenza A virus have been isolated from wild ...

Influenzavirus B ''Influenza B virus'' is the only species in the genus ''Betainfluenzavirus'' in the virus family ''Orthomyxoviridae''. Influenza B virus is known only to infect humans and seals. This limited host range is apparently responsible for the lack o ...

, Junin and Tacaribe virus,

Simian immunodeficiency virus ''Simian immunodeficiency virus'' (''SIV'') is a species of retrovirus that cause persistent infections in at least 45 species of non-human primates. Based on analysis of strains found in four species of monkeys from Bioko Island, which was iso ...

, and (weakly)

Human immunodeficiency virus The human immunodeficiency viruses (HIV) are two species of ''Lentivirus'' (a subgroup of retrovirus) that infect humans. Over time, they cause acquired immunodeficiency syndrome (AIDS), a condition in which progressive failure of the immun ...

types 1 and 2.

References

{{Reflist Cryobiology