Heparin, also known as unfractionated heparin (UFH), is a medication and naturally occurring glycosaminoglycan. Since heparins depend on the activity of antithrombin, they are considered anticoagulants. Specifically it is also used in the treatment of heart attacks and unstable angina. It is given intravenously or by injection under the skin. Other uses for its anticoagulant properties include inside blood specimen test tubes and kidney dialysis machines.
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, although large clinical trials failed to demonstrate any symptomatic benefit of chondroitin.
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 connective tissue.
Glycosaminoglycans (GAGs) or mucopolysaccharides are long, linear polysaccharides consisting of repeating disaccharide units. The repeating two-sugar unit consists of a uronic sugar and an amino sugar, except in the case of the sulfated glycosaminoglycan keratan, where, in place of the uronic sugar there is a galactose unit. GAGs are found in vertebrates, invertebrates and bacteria. Because GAGs are highly polar molecules and attract water; the body uses them as lubricants or shock absorbers.
Glucuronic acid is a uronic acid that was first isolated from urine. It is found in many gums such as gum arabic, xanthan, and kombucha tea and is important for the metabolism of microorganisms, plants and animals.
Idose is a hexose, a six carbon monosaccharide. It has an aldehyde group and is an aldose. It is not found in nature, but its uronic acid, iduronic acid, is important. It is a component of dermatan sulfate and heparan sulfate, which are glycosaminoglycans. The first and third hydroxyls point the opposite way from the second and fourth. It is made by aldol condensation of D- and L-glyceraldehyde. L-Idose is a C-5 epimer of D-glucose.
The terms glycans and polysaccharides 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.
Ground substance is an amorphous gel-like substance in the extracellular space of animals that contains all components of the extracellular matrix (ECM) except for fibrous materials such as collagen and elastin. Ground substance is active in the development, movement, and proliferation of tissues, as well as their metabolism. Additionally, cells use it for support, water storage, binding, and a medium for intercellular exchange. Ground substance provides lubrication for collagen fibers.
Dermatan sulfate is a glycosaminoglycan found mostly in skin, but also in blood vessels, heart valves, tendons, and lungs.
Heparan sulfate (HS) is a linear polysaccharide found in all animal tissues. It occurs as a proteoglycan in which two or three HS chains are attached in close proximity to cell surface or extracellular matrix proteins. In this form, HS binds to a variety of protein ligands, including Wnt, 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. One study suggests that cellular heparan sulfate has a role in SARS-CoV-2 Infection, particularly when the virus attaches with ACE2.
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.
l-Iduronic acid is the major uronic acid component of the glycosaminoglycans (GAGs) dermatan sulfate, and heparin. It is also present in heparan sulfate, although here in a minor amount relative to its carbon-5 epimer glucuronic acid.
The enzyme chondroitin B lyase catalyzes the following process:
The enzyme chondroitin-sulfate-ABC endolyase catalyzes the following process:
In enzymology, a glucuronate-2-sulfatase is an enzyme that catalyzes the chemical reaction of cleaving off the 2-sulfate groups of the 2-O-sulfo-D-glucuronate residues of chondroitin sulfate, heparin and heparitin sulfate.
A xyloside is a type of glycoside derived from the sugar xylose.
Dermatan 4-sulfotransferase is an enzyme with systematic name 3'-phospho-5'-adenylyl sulfate:(dermatan)-N-acetyl-D-galactosamine 4-sulfotransferase. This enzyme catalyses the following chemical reaction
Unsaturated chondroitin disaccharide hydrolase (EC 3.2.1.180, UGL, unsaturated glucuronyl hydrolase) is an enzyme with systematic name beta-D-4-deoxy-Delta4-GlcAp-(1->3)-beta-D-GalNAc6S hydrolase. This enzyme catalyses the following chemical reaction
Stains-all is a carbocyanine dye, which stains anionic proteins, nucleic acids, anionic polysaccharides and other anionic molecules.
Ulvan lyase is an enzyme found within the cell-wall of the marine organism Ulvales, and some marine bacterium. A lyase is a class of enzyme that catalyzes the breakdown of chemical bonds through an elimination reaction mechanism, rather than a substitution reaction mechanism. Ulvan lyase belongs to the polysaccharide lyase family, a type of enzyme that primarily functions to cleave glycosidic linkages in polysaccharides.
