beta-galactoside (CMP) alpha-2,3-sialyltransferase activity
Definition
Target type: molecularfunction
Catalysis of the reaction: CMP-N-acetylneuraminate + beta-D-galactosyl-(1->3)-N-acetyl-alpha-D-galactosaminyl-R = CMP + alpha-N-acetylneuraminyl-(2->3)-beta-D-galactosyl-(1->3)-N-acetyl-alpha-D-galactosaminyl-R. [EC:2.4.3.4]
Beta-galactoside (CMP) alpha-2,3-sialyltransferase activity is a key enzymatic process in the biosynthesis of complex glycoconjugates, including glycoproteins and glycolipids. This enzymatic activity is catalyzed by a family of enzymes known as sialyltransferases, specifically those that transfer sialic acid (N-acetylneuraminic acid, Neu5Ac) from the donor substrate CMP-sialic acid to the acceptor substrate beta-galactoside. The resulting product is a sialylated glycoconjugate with an alpha-2,3 linkage between the sialic acid and the galactose residue. This specific linkage is crucial for the biological functions of many glycoconjugates, including cell adhesion, cell signaling, and immune recognition. The enzyme active site exhibits high specificity for both the donor and acceptor substrates, ensuring the precise addition of sialic acid to the correct position on the glycoconjugate. This specificity is achieved through a combination of amino acid residues that interact with the substrates and contribute to the formation of a transient enzyme-substrate complex. The catalytic mechanism of the reaction involves the transfer of sialic acid from CMP-sialic acid to the hydroxyl group of the galactose residue, accompanied by the release of CMP. This process is highly regulated, influenced by factors such as the availability of substrates, the presence of cofactors, and the expression levels of the sialyltransferase enzyme. Dysregulation of this enzymatic activity can lead to a variety of pathological conditions, including cancer, inflammation, and autoimmune diseases. The study of beta-galactoside (CMP) alpha-2,3-sialyltransferase activity provides valuable insights into the complex process of glycoconjugate biosynthesis, its role in cell function, and its potential implications for human health.'
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Proteins (2)
| Protein | Definition | Taxonomy |
|---|---|---|
| CMP-N-acetylneuraminate-beta-galactosamide-alpha-2,3-sialyltransferase 1 | A CMP-N-acetylneuraminate-beta-galactosamide-alpha-2,3-sialyltransferase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q11201] | Homo sapiens (human) |
| CMP-N-acetylneuraminate-beta-galactosamide-alpha-2,3-sialyltransferase 1 | A CMP-N-acetylneuraminate-beta-galactosamide-alpha-2,3-sialyltransferase 1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q11201] | Homo sapiens (human) |
Compounds (11)
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| 2,3-dihydroxybenzoic acid | 2,3-dihydroxybenzoic acid : A dihydroxybenzoic acid that is benzoic acid substituted by hydroxy groups at positions 2 and 3. It occurs naturally in Phyllanthus acidus and in the aquatic fern Salvinia molesta. 2,3-dihydroxybenzoic acid: RN given refers to parent cpd dihydroxybenzoic acid : Any member of the class of hydroxybenzoic acids carrying two phenolic hydroxy groups on the benzene ring and its derivatives. | dihydroxybenzoic acid | human xenobiotic metabolite; plant metabolite |
| protocatechuic acid | 3,4-dihydroxybenzoic acid : A dihydroxybenzoic acid in which the hydroxy groups are located at positions 3 and 4. protocatechuic acid: RN given refers to parent cpd; structure | catechols; dihydroxybenzoic acid | antineoplastic agent; EC 1.1.1.25 (shikimate dehydrogenase) inhibitor; EC 1.14.11.2 (procollagen-proline dioxygenase) inhibitor; human xenobiotic metabolite; plant metabolite |
| gallic acid | gallate : A trihydroxybenzoate that is the conjugate base of gallic acid. | trihydroxybenzoic acid | antineoplastic agent; antioxidant; apoptosis inducer; astringent; cyclooxygenase 2 inhibitor; EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor; geroprotector; human xenobiotic metabolite; plant metabolite |
| beta-resorcylic acid | beta-resorcylic acid: RN given refers to parent cpd; structure | ||
| 2,5-dihydroxybenzoic acid | 2,5-dihydroxybenzoic acid : A dihydroxybenzoic acid having the two hydroxy groups at the 2- and 5-positions. 2,5-dihydroxybenzoic acid: RN given refers to parent cpd; a oxidative product of saligenin | dihydroxybenzoic acid | EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor; fungal metabolite; human metabolite; MALDI matrix material; mouse metabolite |
| veratric acid | 3,4-dimethoxybenzoic acid : A member of the class of benzoic acids that is benzoic acid substituted by methoxy groups at positions 2 and 3. veratric acid: RN given refers to parent cpd; structure | benzoic acids | allergen; plant metabolite |
| methyl gallate | methyl 3,4,5-trihydroxybenzoate : A gallate ester obtained by the formal condensation of gallic acid with methanol. It exhibits anti-oxidant, anti-tumor, anti-microbial and anti-inflammatory properties. methyl gallate: has both immunosuppressive and phytogenic antineoplastic activities; isolated from Acer saccharinum | gallate ester | anti-inflammatory agent; antioxidant; plant metabolite |
| 3,4,5-trimethoxybenzoic acid | 3,4,5-trimethoxybenzoic acid : A benzoic acid derivative carrying 3-, 4- and 5-methoxy substituents. 3,4,5-trimethoxybenzoic acid: RN given refers to parent cpd; structure | benzoic acids; methoxybenzenes | human urinary metabolite; human xenobiotic metabolite; plant metabolite |
| syringic acid | syringic acid : A dimethoxybenzene that is 3,5-dimethyl ether derivative of gallic acid. syringic acid: RN given refers to parent cpd; structure in third source | benzoic acids; dimethoxybenzene; phenols | plant metabolite |
| epigallocatechin gallate | (-)-epigallocatechin 3-gallate : A gallate ester obtained by the formal condensation of gallic acid with the (3R)-hydroxy group of (-)-epigallocatechin. epigallocatechin gallate: a steroid 5alpha-reductase inhibitor and antimutagen in green tea (Camellia sinensis) | flavans; gallate ester; polyphenol | antineoplastic agent; antioxidant; apoptosis inducer; geroprotector; Hsp90 inhibitor; neuroprotective agent; plant metabolite |
| guanosine diphosphate | Guanosine Diphosphate: A guanine nucleotide containing two phosphate groups esterified to the sugar moiety. | guanosine 5'-phosphate; purine ribonucleoside 5'-diphosphate | Escherichia coli metabolite; mouse metabolite; uncoupling protein inhibitor |