Xyloside

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A xyloside is a type of glycoside derived from the sugar xylose.

Glycoside molecule in which a sugar is bound to another functional group

In chemistry, a glycoside is a molecule in which a sugar is bound to another functional group via a glycosidic bond. Glycosides play numerous important roles in living organisms. Many plants store chemicals in the form of inactive glycosides. These can be activated by enzyme hydrolysis, which causes the sugar part to be broken off, making the chemical available for use. Many such plant glycosides are used as medications. Several species of Heliconius butterfly are capable of incorporating these plant compounds as a form of chemical defense against predators. In animals and humans, poisons are often bound to sugar molecules as part of their elimination from the body.

Xylose chemical compound

Xylose is a sugar first isolated from wood, and named for it. Xylose is classified as a monosaccharide of the aldopentose type, which means that it contains five carbon atoms and includes an aldehyde functional group. It is derived from hemicellulose, one of the main constituents of biomass. Like most sugars, it can adopt several structures depending on conditions. With its free aldehyde group, it is a reducing sugar.

Proteoglycan (PG) synthesis is initiated by the transfer of D-xylose from UDP-xylose to a serine residue in core proteins. This natural primer acts as a template for the assembly of heparin sulfate, heparin, chondroitin sulfate, and dermatan sulfate side chains, depending on the tissue. However, in 1973 it was determined that synthetic B-D-xylosides can prime glycosaminoglycan (GAG) synthesis by substituting for the core xylosylated protein.

Proteoglycan

Proteoglycans are proteins that are heavily glycosylated. The basic proteoglycan unit consists of a "core protein" with one or more covalently attached glycosaminoglycan (GAG) chain(s). The point of attachment is a serine (Ser) residue to which the glycosaminoglycan is joined through a tetrasaccharide bridge. The Ser residue is generally in the sequence -Ser-Gly-X-Gly-, although not every protein with this sequence has an attached glycosaminoglycan. The chains are long, linear carbohydrate polymers that are negatively charged under physiological conditions due to the occurrence of sulfate and uronic acid groups. Proteoglycans occur in the connective tissue.

Serine is an ɑ-amino acid that is used in the biosynthesis of proteins. It contains an α-amino group, a carboxyl group, and a side chain consisting of a hydroxymethyl group, classifying it as a polar amino acid. It can be synthesized in the human body under normal physiological circumstances, making it a nonessential amino acid. It is encoded by the codons UCU, UCC, UCA, UCG, AGU and AGC.

Heparin anticoagulant

Heparin, also known as unfractionated heparin (UFH), is a medication which is used as an anticoagulant. Specifically it is used to treat and prevent deep vein thrombosis, pulmonary embolism, and arterial thromboembolism. It is also used in the treatment of heart attacks and unstable angina. It is given by injection into a vein or under the skin. Other uses include inside test tubes and kidney dialysis machines.

Many Beta-D-xylosides have been studied for use as xylose primes with varying results. [1]

  1. Priming requires the Beta-anomer of xylose. [2]
  2. Priming activity correlates with the activity of the aglycone (cite).
  3. The most active xyloside primers contain O or S in glycosidic linkage. [3]
  4. Priming is dose dependent. [4] [5]
  5. Beta-D-xylosides prime GAGs in most cells.
  6. Most of the material created from Beta-D-xylosides priming is excreted into the growth media.
  7. Beta-D-xylosides prime chondroitin sulfate or dermatan sulfate whereas priming of heparin sulfate poorly, except with the appropriate aglycones. [5] [6]

Beta-D-xylosides consist of a xylose in beta linkage to an aglycone. The aglycone often consists of a hydrophobic compound which aids in carrying the sugar moiety to the golgi membrane where GAG synthesis takes place.

Golgi apparatus A compound membranous cytoplasmic organelle of eukaryotic cells, consisting of flattened, ribosome-free vesicles arranged in a more or less regular stack. The Golgi apparatus differs from the endoplasmic reticulum in often having slightly thicker mem

The Golgi apparatus, also known as the Golgi complex, Golgi body, or simply the Golgi, is an organelle found in most eukaryotic cells. It was identified in 1897 by the Italian scientist Camillo Golgi and named after him in 1898.

List of xylosides

Related Research Articles

Chondroitin sulfate sulfated glycosaminoglycan

Chondroitin sulfate is a sulfated glycosaminoglycan (GAG) composed of a chain of alternating sugars. It is usually found attached to proteins as part of a proteoglycan. A chondroitin chain can have over 100 individual sugars, each of which can be sulfated in variable positions and quantities. Chondroitin sulfate is an important structural component of cartilage and provides much of its resistance to compression. Along with glucosamine, chondroitin sulfate has become a widely used dietary supplement for treatment of osteoarthritis.

Glycosaminoglycan long unbranched polysaccharides consisting of a repeating disaccharide unit

Glycosaminoglycans (GAGs) or mucopolysaccharides are long unbranched polysaccharides consisting of a repeating disaccharide unit. The repeating unit consists of an amino sugar along with a uronic sugar or galactose. Glycosaminoglycans are highly polar and attract water. They are therefore useful to the body as a lubricant or as a shock absorber.

The terms glycan and polysaccharide are defined by IUPAC as synonyms meaning "compounds consisting of a large number of monosaccharides linked glycosidically". However, in practice the term glycan may also be used to refer to the carbohydrate portion of a glycoconjugate, such as a glycoprotein, glycolipid, or a proteoglycan, even if the carbohydrate is only an oligosaccharide. Glycans usually consist solely of O-glycosidic linkages of monosaccharides. For example, cellulose is a glycan composed of β-1,4-linked D-glucose, and chitin is a glycan composed of β-1,4-linked N-acetyl-D-glucosamine. Glycans can be homo- or heteropolymers of monosaccharide residues, and can be linear or branched.

Heparan sulfate polymer

Heparan sulfate (HS) is a linear polysaccharide found in all animal tissues. It occurs as a proteoglycan (HSPG) in which two or three HS chains are attached in close proximity to cell surface or extracellular matrix proteins. It is in this form that HS binds to a variety of protein ligands and regulates a wide range of biological activities, including developmental processes, angiogenesis, blood coagulation, abolishing detachment activity by GrB, and tumour metastasis. HS has also been shown to serve as cellular receptor for a number of viruses including the respiratory syncytial virus.

Heparinoids are glycosaminoglycans which are derivatives of heparin. They include oligosaccharides and sulfated polysaccharides of plant, animal, or synthetic origin. One study conducted on heparinoids.

Heparin cofactor II protein-coding gene in the species Homo sapiens

Heparin cofactor II (HCII), a protein encoded by the SERPIND1 gene, is a coagulation factor that inhibits IIa, and is a cofactor for heparin and dermatan sulfate.

Sulfation or sulfurylation in biochemistry is the enzyme-catalyzed conjugation of a sulfo group to another molecule. This biotransformation involves a sulfotransferase enzyme catalyzing the transfer of a sulfo group from a donor cosubstrate, usually 3'-phosphoadenosine-5'-phosphosulfate (PAPS), to a substrate molecule's hydroxyl or amine. Sulfation is involved in a variety of biological processes, including detoxification, hormone regulation, molecular recognition, cell signaling, and viral entry into cells. It is among the reactions in phase II drug metabolism, frequently effective in rendering a xenobiotic less active from a pharmacological and toxicological standpoint, but sometimes playing a role in the activation of xenobiotics. Another example of biological sulfation is in the synthesis of sulfonated glycosaminoglycans, such as heparin, heparan sulfate, chondroitin sulfate, and dermatan sulfate. Sulfation is also a possible posttranslational modification of proteins.

Arylsulfatase B protein-coding gene in the species Homo sapiens

Arylsulfatase B is an enzyme associated with mucopolysaccharidosis VI.

Syndecan 1 protein-coding gene in the species Homo sapiens

Syndecan 1 is a protein which in humans is encoded by the SDC1 gene.

In enzymology, a galactosylxylosylprotein 3-beta-galactosyltransferase is an enzyme that catalyzes the chemical reaction

In enzymology, a xylosylprotein 4-beta-galactosyltransferase is an enzyme that catalyzes the chemical reaction

In enzymology, a protein xylosyltransferase is an enzyme that catalyzes the chemical reaction in which a beta-D-xylosyl residue is transferred from UDP-D-xylose to the sidechain oxygen atom of a serine residue in a protein.

XYLT1 protein-coding gene in the species Homo sapiens

Xylosyltransferase 1 is an enzyme that in humans is encoded by the XYLT1 gene.

B4GALT7 protein-coding gene in the species Homo sapiens

Beta-1,4-galactosyltransferase 7 also known as galactosyltransferase I is an enzyme that in humans is encoded by the B4GALT7 gene. Galactosyltransferase I catalyzes the synthesis of the glycosaminoglycan-protein linkage in proteoglycans. Proteoglycans in turn are structural components of the extracellular matrix that is found between cells in connective tissues.

B3GAT3 protein-coding gene in the species Homo sapiens

Galactosylgalactosylxylosylprotein 3-beta-glucuronosyltransferase 3 is an enzyme that in humans is encoded by the B3GAT3 gene.

XYLT2 protein-coding gene in the species Homo sapiens

Xylosyltransferase 2 is an enzyme that in humans is encoded by the XYLT2 gene.

ChGn protein-coding gene in the species Homo sapiens

Chondroitin sulfate N-acetylgalactosaminyltransferase 1 is an enzyme that in humans is encoded by the CSGALNACT1 gene.

Carbohydrate sulfotransferase

Carbohydrate sulfotransferases are sulfotransferase enzymes that transfer sulfate to carbohydrate groups in glycoproteins and glycolipids. Carbohydrates are used by cells for a wide range of functions from structural purposes to extracellular communication. Carbohydrates are suitable for such a wide variety of functions due to the diversity in structure generated from monosaccharide composition, glycosidic linkage positions, chain branching, and covalent modification. Possible covalent modifications include acetylation, methylation, phosphorylation, and sulfation. Sulfation, performed by carbohydrate sulfotransferases, generates carbohydrate sulfate esters. These sulfate esters are only located extracellularly, whether through excretion into the extracellular matrix (ECM) or by presentation on the cell surface. As extracellular compounds, sulfated carbohydrates are mediators of intercellular communication, cellular adhesion, and ECM maintenance.

Glucuronylgalactosylproteoglycan 4-beta-N-acetylgalactosaminyltransferase is an enzyme with systematic name UDP-N-acetyl-D-galactosamine:D-glucuronyl-(1->3)-beta-D-galactosyl-proteoglycan 4-beta-N-acetylgalactosaminyltransferase. This enzyme catalyses the following chemical reaction

References

  1. ↑ Esko and Montgomery 1995
  2. ↑ Galligani et al. 1975
  3. ↑ Sobue et al. 1987
  4. ↑ Esko et al. 1987
  5. 1 2 Lugemwa and Esko 1991
  6. ↑ Fritz et al., 1994
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