Target type: molecularfunction
Catalysis of the hydrolysis of alpha-(2->8)-glycosidic linkages of terminal sialic residues in substrates. [EC:3.2.1.18, GOC:mengo_curators]
Exo-alpha-(1-u003e2)-mannanases are glycosyl hydrolases that cleave the alpha-(1-u003e2)-linkages in mannans. Specifically, they hydrolyze the terminal alpha-(1-u003e2)-linked mannose residue from the non-reducing end of mannans. These enzymes play a crucial role in the degradation of mannans, which are complex polysaccharides found in the cell walls of plants, fungi, and bacteria.
Exo-alpha-(1-u003e2)-mannanases are often found in microorganisms, including bacteria and fungi. They are involved in various processes, such as the breakdown of plant cell walls for nutrient acquisition, the production of biofuels from biomass, and the modification of polysaccharides for industrial applications.
The catalytic mechanism of exo-alpha-(1-u003e2)-mannanases involves the formation of a covalent intermediate between the enzyme and the substrate. This intermediate is then hydrolyzed to release the cleaved mannose residue and the enzyme. The active site of exo-alpha-(1-u003e2)-mannanases typically contains an acidic residue, such as glutamate or aspartate, which acts as a general acid catalyst.
These enzymes are important targets for the development of new antibiotics, antifungals, and biocatalysts. Their specific activity against mannans makes them valuable tools for the modification and degradation of these polysaccharides in various industrial applications.
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| Protein | Definition | Taxonomy |
|---|---|---|
| Sialidase-2 | A sialidase-2 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9Y3R4] | Homo sapiens (human) |
| Sialidase-3 | A sialidase-3 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q9UQ49] | Homo sapiens (human) |
| Sialidase-1 | A sialidase-1 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q99519] | Homo sapiens (human) |
| Sialidase-4 | A sialidase-4 that is encoded in the genome of human. [PRO:DNx, UniProtKB:Q8WWR8] | Homo sapiens (human) |
| Compound | Definition | Classes | Roles |
|---|---|---|---|
| danthron | chrysazin : A dihydroxyanthraquinone that is anthracene-9,10-dione substituted by hydroxy groups at positions 1 and 8. danthron: structure | dihydroxyanthraquinone | apoptosis inducer; plant metabolite |
| emodin | emodin : A trihydroxyanthraquinone that is 9,10-anthraquinone which is substituted by hydroxy groups at positions 1, 3, and 8 and by a methyl group at position 6. It is present in the roots and barks of numerous plants (particularly rhubarb and buckthorn), moulds, and lichens. It is an active ingredient of various Chinese herbs. Emodin: Purgative anthraquinone found in several plants, especially RHAMNUS PURSHIANA. It was formerly used as a laxative, but is now used mainly as a tool in toxicity studies. | trihydroxyanthraquinone | antineoplastic agent; laxative; plant metabolite; tyrosine kinase inhibitor |
| carzenide | sulfonamide | ||
| rhein | dihydroxyanthraquinone | ||
| zanamivir | Zanamivir: A guanido-neuraminic acid that is used to inhibit NEURAMINIDASE. | guanidines | antiviral agent; EC 3.2.1.18 (exo-alpha-sialidase) inhibitor |
| oseltamivir | oseltamivir : A cyclohexenecarboxylate ester that is the ethyl ester of oseltamivir acid. An antiviral prodrug (it is hydrolysed to the active free carboxylic acid in the liver), it is used to slow the spread of influenza. Oseltamivir: An acetamido cyclohexene that is a structural homolog of SIALIC ACID and inhibits NEURAMINIDASE. | acetamides; amino acid ester; cyclohexenecarboxylate ester; primary amino compound | antiviral drug; EC 3.2.1.18 (exo-alpha-sialidase) inhibitor; environmental contaminant; prodrug; xenobiotic |
| 2-deoxy-2,3-dehydro-n-acetylneuraminic acid | 2-deoxy-2,3-dehydro-N-acetylneuraminic acid : N-Acetylneuraminic acid reduced across the 2,3-bond with loss of the hydroxy group at C-2; it is a minor component of body fluids although abundant in sialuria. 2-deoxy-2,3-dehydro-N-acetylneuraminic acid: also known as NeuAc2en, but this is also synonym for another compound | N-acetylneuraminic acids | |
| 9,10-anthraquinone 2-carboxylic acid | 9,10-anthraquinone 2-carboxylic acid: structure in first source | ||
| 5-hydroxyflavone | flavones | ||
| (-)-catechin | (-)-catechin : The (-)-enantiomer of catechin. | catechin | metabolite |
| sakuranetin | sakuranetin : A flavonoid phytoalexin that is (S)-naringenin in which the hydroxy group at position 7 is replaced by a methoxy group. sakuranetin: major rice phytoalexin; RN given for ((S)-(-))-isomer; structure in first source | (2S)-flavan-4-one; 4'-hydroxyflavanones; dihydroxyflavanone; flavonoid phytoalexin; monomethoxyflavanone | antimycobacterial drug; plant metabolite |
| bcx 1812 | 3-hydroxy monocarboxylic acid; acetamides; cyclopentanols; guanidines | antiviral drug; EC 3.2.1.18 (exo-alpha-sialidase) inhibitor | |
| n-acetylneuraminic acid | N-acetylneuraminic acid : An N-acylneuraminic acid where the N-acyl group is specified as acetyl. N-Acetylneuraminic Acid: An N-acyl derivative of neuraminic acid. N-acetylneuraminic acid occurs in many polysaccharides, glycoproteins, and glycolipids in animals and bacteria. (From Dorland, 28th ed, p1518) | N-acetylneuraminic acids | antioxidant; bacterial metabolite; EC 3.2.1.18 (exo-alpha-sialidase) inhibitor; human metabolite; mouse metabolite |
| n-acetylneuraminic acid | N-acetyl-beta-neuraminic acid : N-Acetylneuraminic acid with beta configuration at the anomeric centre. | N-acetylneuraminic acid | epitope |
| 4-amino-2-deoxy-2,3-didehydro-n-acetylneuraminic acid | |||
| bana 113 | |||
| quercetin | 7-hydroxyflavonol; pentahydroxyflavone | antibacterial agent; antineoplastic agent; antioxidant; Aurora kinase inhibitor; chelator; EC 1.10.99.2 [ribosyldihydronicotinamide dehydrogenase (quinone)] inhibitor; geroprotector; phytoestrogen; plant metabolite; protein kinase inhibitor; radical scavenger | |
| acacetin | 5,7-dihydroxy-4'-methoxyflavone : A monomethoxyflavone that is the 4'-methyl ether derivative of apigenin. | dihydroxyflavone; monomethoxyflavone | anticonvulsant; plant metabolite |
| apigenin | Chamomile: Common name for several daisy-like plants (MATRICARIA; TRIPLEUROSPERMUM; ANTHEMIS; CHAMAEMELUM) native to Europe and Western Asia, now naturalized in the United States and Australia. | trihydroxyflavone | antineoplastic agent; metabolite |
| luteolin | 3'-hydroxyflavonoid; tetrahydroxyflavone | angiogenesis inhibitor; anti-inflammatory agent; antineoplastic agent; apoptosis inducer; c-Jun N-terminal kinase inhibitor; EC 2.3.1.85 (fatty acid synthase) inhibitor; immunomodulator; nephroprotective agent; plant metabolite; radical scavenger; vascular endothelial growth factor receptor antagonist | |
| kaempferol | 7-hydroxyflavonol; flavonols; tetrahydroxyflavone | antibacterial agent; geroprotector; human blood serum metabolite; human urinary metabolite; human xenobiotic metabolite; plant metabolite | |
| genistein | 7-hydroxyisoflavones | antineoplastic agent; EC 5.99.1.3 [DNA topoisomerase (ATP-hydrolysing)] inhibitor; geroprotector; human urinary metabolite; phytoestrogen; plant metabolite; tyrosine kinase inhibitor | |
| baicalein | trihydroxyflavone | angiogenesis inhibitor; anti-inflammatory agent; antibacterial agent; anticoronaviral agent; antifungal agent; antineoplastic agent; antioxidant; apoptosis inducer; EC 1.13.11.31 (arachidonate 12-lipoxygenase) inhibitor; EC 1.13.11.33 (arachidonate 15-lipoxygenase) inhibitor; EC 3.4.21.26 (prolyl oligopeptidase) inhibitor; EC 3.4.22.69 (SARS coronavirus main proteinase) inhibitor; EC 4.1.1.17 (ornithine decarboxylase) inhibitor; ferroptosis inhibitor; geroprotector; hormone antagonist; plant metabolite; prostaglandin antagonist; radical scavenger | |
| chrysin | chrysin : A dihydroxyflavone in which the two hydroxy groups are located at positions 5 and 7. | 7-hydroxyflavonol; dihydroxyflavone | anti-inflammatory agent; antineoplastic agent; antioxidant; EC 2.7.11.18 (myosin-light-chain kinase) inhibitor; hepatoprotective agent; plant metabolite |
| genkwanin | genkwanin : A monomethoxyflavone that is apigenin in which the hydroxy group at position 7 is methylated. genkwanin: structure | dihydroxyflavone; monomethoxyflavone | metabolite |
| myricetin | 7-hydroxyflavonol; hexahydroxyflavone | antineoplastic agent; antioxidant; cyclooxygenase 1 inhibitor; food component; geroprotector; hypoglycemic agent; plant metabolite | |
| scutellarein | scutellarein : Flavone substituted with hydroxy groups at C-4', -5, -6 and -7. scutellarein: aglycone of scutellarin from Scutellaria baicalensis; carthamidin is 2S isomer of scutellarein; do not confuse with isoscutellarein and/or isocarthamidin which are respective regioisomers, or with the scutelarin protein | tetrahydroxyflavone | metabolite |
| tricetin | tricetin : Flavone hydroxylated at positions 3', 4', 5, 5' and 7. | pentahydroxyflavone | antineoplastic agent; metabolite |
| 4',7-dihydroxyflavone | 4',7-dihydroxyflavone : A dihydroxyflavone in which the two hydroxy substituents are located at positions 4' and 7. 4',7-dihydroxyflavone: inducer of nod gene | dihydroxyflavone | metabolite |
| 5,7,2'-trihydroxyflavone | 5,7,2'-trihydroxyflavone: has inhibitory effects on the EBV-EA activation & on mouse skin tumor promotion in an in vivo two-stage carcinogenesis test; from Scutellaria baicalensis; structure given in first source | flavones |