Fucose

Fucose is a type of sugar, specifically an aldose sugar, that plays a crucial role in various biological processes[1]. It is unique among naturally occurring sugars in mammals due to its L-configuration, whereas all other sugars have a D-configuration[2]. Fucose is also structurally distinct in lacking a hydroxyl group on the C-6 carbon, which distinguishes it from other sugars like D-galactose[2].

Biological Functions

Fucose is present in a variety of glycolipids and glycoproteins produced by mammalian cells[2]. It is incorporated into the terminal portions of N-glycans, O-glycans, and glycolipids by 13 fucosyltransferases, which utilize the nucleotide-charged form, GDP-fucose, to modify targets[2]. Fucose modifications have been implicated in many biological functions, including immunity and cancer[2]. Congenital mutations of a Golgi apparatus localized GDP-fucose transporter cause leukocyte adhesion deficiency type II, which results in severe developmental and immune deficiencies, highlighting the important role fucose plays in these processes[2].

Importance in Mammalian Physiology and Pathophysiology

Fucose-containing glycans have important roles in blood transfusion reactions, selectin-mediated leukocyte-endothelial adhesion, host-microbe interactions, and numerous ontogenic events, including signaling events by the Notch receptor family[5]. Alterations in the expression of fucosylated oligosaccharides have also been observed in several pathological processes, including cancer and atherosclerosis[5]. Fucose deficiency is accompanied by a complex set of phenotypes both in humans with leukocyte adhesion deficiency type II (LAD II; also known as congenital disorder of glycosylation type IIc) and in a recently generated strain of mice with a conditional defect in fucosylated glycan expression[5].

Applications

L-Fucose has several potential applications in cosmetics, pharmaceuticals, and dietary supplements[4]. Fucosylation of antibodies has been established to reduce binding to the Fc receptor of Natural Killer cells and thereby reduce antigen-dependent cellular cytotoxicity[4]. Therefore, afucosylated monoclonal antibodies have been designed to recruit the immune system to cancer cells, enhancing the in vivo cell killing[4].

In summary, fucose is a unique sugar with important biological functions in mammalian physiology and pathophysiology, particularly in immunity and cancer. Its deficiency can lead to severe developmental and immune deficiencies, and it has potential applications in various fields.

Citations:

[1] https://www.merriam-webster.com/dictionary/fucose

[2] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5458543/

[3] https://academic.oup.com/glycob/article/13/7/41R/612936

[4] https://en.wikipedia.org/wiki/Fucose

[5] https://pubmed.ncbi.nlm.nih.gov/12651883/