Fucose is a
hexose
In chemistry, a hexose is a monosaccharide (simple sugar) with six carbon atoms. The chemical formula for all hexoses is C6H12O6, and their molecular weight is 180.156 g/mol.
Hexoses exist in two forms, open-chain or cyclic, that easily convert ...
deoxy sugar
Deoxy sugars are sugars that have had a hydroxyl group replaced with a hydrogen atom.
Examples include:
* Deoxyribose, or 2-deoxy-D-ribose, a constituent of DNA
* Fucose, or 6-deoxy-L-galactose, main component of fucoidan of brown algae, and p ...
with the
chemical formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, ...
C
6H
12O
5. It is found on
''N''-linked glycans on the
mammal
Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...
ian,
insect
Insects (from Latin ') are pancrustacean hexapod invertebrates of the class Insecta. They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body ( head, thorax and abdomen), three pairs ...
and
plant
Plants are predominantly photosynthetic eukaryotes of the kingdom Plantae. Historically, the plant kingdom encompassed all living things that were not animals, and included algae and fungi; however, all current definitions of Plantae exclud ...
cell surface. Fucose is the fundamental sub-unit of the
seaweed
Seaweed, or macroalgae, refers to thousands of species of macroscopic, multicellular, marine algae. The term includes some types of '' Rhodophyta'' (red), ''Phaeophyta'' (brown) and ''Chlorophyta'' (green) macroalgae. Seaweed species such as ...
polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wa ...
fucoidan
Fucoidan is a long chain sulfated polysaccharide found in various species of brown algae. Commercially available fucoidan is commonly extracted from the seaweed species '' Fucus vesiculosus'', ''Cladosiphon okamuranus'', ''Laminaria japonica'' and ...
. The
α(1→3) linked core of fucose is a suspected
carbohydrate
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 ...
antigen
In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. ...
for
IgE
Immunoglobulin E (IgE) is a type of antibody (or immunoglobulin (Ig) " isotype") that has been found only in mammals. IgE is synthesised by plasma cells. Monomers of IgE consist of two heavy chains (ε chain) and two light chains, with the ε c ...
-mediated
allergy
Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...
.
Two structural features distinguish fucose from other six-carbon sugars present in mammals: the lack of a
hydroxyl
In chemistry, a hydroxy or hydroxyl group is a functional group with the chemical formula and composed of one oxygen atom covalently bonded to one hydrogen atom. In organic chemistry, alcohols and carboxylic acids contain one or more hydroxy ...
group on the carbon at the 6-position (C-6) (thereby making it a
deoxy sugar
Deoxy sugars are sugars that have had a hydroxyl group replaced with a hydrogen atom.
Examples include:
* Deoxyribose, or 2-deoxy-D-ribose, a constituent of DNA
* Fucose, or 6-deoxy-L-galactose, main component of fucoidan of brown algae, and p ...
) and the
L -configuration. It is equivalent to 6-deoxy--
galactose
Galactose (, '' galacto-'' + '' -ose'', "milk sugar"), sometimes abbreviated Gal, is a monosaccharide sugar that is about as sweet as glucose, and about 65% as sweet as sucrose. It is an aldohexose and a C-4 epimer of glucose. A galactose molec ...
.
In the fucose-containing glycan structures, fucosylated glycans, fucose can exist as a terminal modification or serve as an attachment point for adding other sugars.
In human ''N''-linked glycans, fucose is most commonly linked α-1,6 to the reducing terminal β-''N''-acetylglucosamine. However, fucose at the non-reducing termini linked α-1,2 to galactose forms the
H antigen
H antigen can refer to one of various types of antigens having diverse biological functions. H antigen is located on the 19th chromosome in humans, and has a variety of functions and definitions as follows:
* Also known as substance H, H antigen ...
, the substructure of the A and B blood group antigens.
Fucose is released from fucose-containing polymers by an enzyme called α-
fucosidase
Tissue alpha-L-fucosidase is an enzyme that in humans is encoded by the ''FUCA1'' gene.
Alpha-Fucosidase is an enzyme that breaks down fucose.HPRD entr
Fucosidosis is an autosomal recessive lysosomal storage disease caused by defective alpha-L-f ...
found in
lysosome
A lysosome () is a membrane-bound organelle found in many animal cells. They are spherical vesicles that contain hydrolytic enzymes that can break down many kinds of biomolecules. A lysosome has a specific composition, of both its membrane prot ...
s.
-Fucose has several potential applications in cosmetics, pharmaceuticals, and dietary supplements
Fucosylation
Fucosylation is the process of adding fucose sugar units to a molecule. It is a type of glycosylation.
It is important clinically, and high levels of fucosylation have been reported in cancer. In cancer and inflammation there are significant chan ...
of antibodies has been established to reduce binding to the
Fc receptor of
Natural Killer
Natural killer cells, also known as NK cells or large granular lymphocytes (LGL), are a type of cytotoxic lymphocyte critical to the innate immune system that belong to the rapidly expanding family of known innate lymphoid cells (ILC) and represen ...
cells and thereby reduce antigen-dependent cellular cytotoxicity. Therefore,
afucosylated monoclonal antibodies Afucosylated monoclonal antibodies are monoclonal antibodies engineered so that the oligosaccharides in the Fc region of the antibody do not have any fucose sugar units. When antibodies are afucosylated, antibody-dependent cellular cytotoxicity (ADC ...
have been designed to recruit the immune system to cancers cells have been manufactured in cell lines deficient in the enzyme for core fucosylation (
FUT8
Alpha-(1,6)-fucosyltransferase is an enzyme that in humans is encoded by the ''FUT8'' gene
In biology, the word gene (from , ; "... Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation ...
), thereby enhancing the in vivo cell killing.
See also
*
Digitalose
Digitalose is a deoxy sugar that is a component of various cardiac glycosides including thevetin and emicymarin. It was first reported in 1892 as being obtained by the hydrolysis of ''Digtalinum verum''. The chemical structure was first eluci ...
, the methyl ether of
D-fucose
*
Fucitol
Fucitol, also known as L-fucitol, 6-deoxy-L-galactitol, and (2''R'',3''S'',4''R'',5''S'')-hexane-1,2,3,4,5-pentol, is a sugar alcohol derived from fucoidan which is found in the North Atlantic seaweed ''Fucus vesiculosus'' or by the reduction of ...
*
Verotoxin-producing ''Escherichia coli''
References
{{Carbohydrates
Aldohexoses
Deoxy sugars