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, with the exception of keratan, where in the place of the uronic sugar it has galactose. Because GAGs are highly polar and attract water, they are used in the body as a lubricant or shock absorber.
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. It is in this form that 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. A recent study reports that cellular heparan sulfate has a role in SARS-CoV-2 Infection, particularly when the virus attaches with ACE2.
Sulfatases EC 3.1.6.- are enzymes of the esterase class that catalyze the hydrolysis of sulfate esters. These may be found on a range of substrates, including steroids, carbohydrates and proteins. Sulfate esters may be formed from various alcohols and amines. In the latter case the resultant N-sulfates can also be termed sulfamates.
Sulfotransferases (SULTs) are transferase enzymes that catalyze the transfer of a sulfo group from a donor molecule to an acceptor alcohol or amine. The most common sulfo group donor is 3'-phosphoadenosine-5'-phosphosulfate (PAPS). In the case of alcohol as acceptor, the product is a sulfate (R-OSO3−), whereas an amine leads to a sulfamate (R-NH-SO3−). Both reactive groups for a sulfonation via sulfotransferases may be part of a protein, lipid, carbohydrate or steroid.
N-acetylglucosamine-6-sulfatase also known as glucosamine (N-acetyl)-6-sulfatase is an enzyme that in humans is encoded by the GNS gene. This enzyme is deficient in Sanfilippo Syndrome type IIId. This enzyme catalyses the following chemical reaction:
In enzymology, a [heparan sulfate]-glucosamine 3-sulfotransferase 1 is an enzyme that catalyzes the chemical reaction
In enzymology, a [heparan sulfate]-glucosamine 3-sulfotransferase 2 is an enzyme that catalyzes the chemical reaction
In enzymology, a [heparan sulfate]-glucosamine 3-sulfotransferase 3 is an enzyme that catalyzes the chemical reaction
In enzymology, a [heparan sulfate]-glucosamine N-sulfotransferase is an enzyme that catalyzes the chemical reaction
Bifunctional heparan sulfate N-deacetylase/N-sulfotransferase 1 is an enzyme. In humans, it is encoded by the NDST1 gene.
Heparan sulfate glucosamine 3-O-sulfotransferase 3A1 is an enzyme that in humans is encoded by the HS3ST3A1 gene.
Heparan sulfate glucosamine 3-O-sulfotransferase 1 is an enzyme that in humans is encoded by the HS3ST1 gene.
Bifunctional heparan sulfate N-deacetylase/N-sulfotransferase 2 is an enzyme that in humans is encoded by the NDST2 gene.
Heparan sulfate 2-O-sulfotransferase 1 is an enzyme that in humans is encoded by the HS2ST1 gene.
Heparan sulfate glucosamine 3-O-sulfotransferase 3B1 is an enzyme that in humans is encoded by the HS3ST3B1 gene. Heparan sulfate biosynthetic enzymes are key components in generating myriad distinct heparan sulfate fine structures that carry out multiple biologic activities. The enzyme encoded by this gene is a member of the heparan sulfate biosynthetic enzyme family. It is a type II integral membrane protein and possesses heparan sulfate glucosaminyl 3-O-sulfotransferase activity ( HS3ST3A1). The Sulfotransferase domain of this enzyme is highly similar to the same domain of heparan sulfate D-glucosaminyl 3-O-sulfotransferase 3A1 and these two enzymes sulfate an identical disaccharide. This gene is widely expressed, with the most abundant expression in liver and placenta.
Bifunctional heparan sulfate N-deacetylase/N-sulfotransferase 3 is an enzyme that in humans is encoded by the NDST3 gene. It catalyses the reaction:
3'-phosphoadenylyl sulfate + α-D-glucosaminyl-[heparan sulfate](n) = adenosine 3',5'-bisphosphate + 2 H+ + N-sulfo-α-D-glucosaminyl-[heparan sulfate](n)
Heparan sulfate glucosamine 3-O-sulfotransferase 2 is an enzyme that in humans is encoded by the HS3ST2 gene.
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.
Heparan sulfate 2-O-sulfotransferase is a sulfotransferase enzyme. Heparan sulfate (HS) is a long unbranched polysaccharide found covalently attached to various proteins at the cell surface and in the extracellular matrix, where it acts as a co-receptor for a number of growth factors, morphogens, and adhesion proteins. HS-O-sulfotransferase (Hs2st) occupies a critical position in the succession of enzymes responsible for the biosynthesis of HS, catalysing the transfer of sulfate to the C2-position of selected hexuronic acid residues within the nascent HS chain. Mice that lack HS2ST undergo developmental failure after midgestation, the most dramatic effect being the complete failure of kidney development. This family is related to InterPro: IPR005331.
3'-phosphoadenylyl-sulfate:(heparan sulfate)-glucosamine 3-sulfotransferase may refer to:
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