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Your query returned 4 entries. Printable version
EC | 3.2.1.81 | ||||||||||||
Accepted name: | β-agarase | ||||||||||||
Reaction: | Hydrolysis of (1→4)-β-D-galactosidic linkages in agarose, giving the tetramer as the predominant product | ||||||||||||
Glossary: | agarose = a linear polysaccharide produced by some members of the Rhodophyta (red algae) made up from alternating D-galactose and 3,6-anhydro-α-L-galactopyranose residues joined by α-(1→3)- and β-(1→4)-linkages. In the field of oligosaccharides derived from agarose, carrageenans, etc., in which alternate residues are 3,6-anhydro sugars, the prefix ’neo’ designates an oligosaccharide whose non-reducing end is the anhydro sugar, and the absence of this prefix means that it is not. For example: neoagarobiose = 3,6-anhydro-α-L-galactopyranosyl-(1→3)-D-galactose agarobiose = β-D-galactopyranosyl-(1→4)-3,6-anhydro-L-galactose |
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Other name(s): | agarase (ambiguous); AgaA; AgaB; endo-β-agarase; agarose 3-glycanohydrolase (incorrect) | ||||||||||||
Systematic name: | agarose 4-glycanohydrolase | ||||||||||||
Comments: | Also acts on porphyran, but more slowly [1]. This enzyme cleaves the β-(1→4) linkages of agarose in a random manner with retention of the anomeric-bond configuration, producing β-anomers that give rise progressively to α-anomers when mutarotation takes place [6]. The end products of hydrolysis are neoagarotetraose and neoagarohexaose in the case of AgaA from the marine bacterium Zobellia galactanivorans, and neoagarotetraose and neoagarobiose in the case of AgaB [6]. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 37288-57-6 | ||||||||||||
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EC | 3.2.1.158 | ||||||||||||
Accepted name: | α-agarase | ||||||||||||
Reaction: | Endohydrolysis of (1→3)-α-L-galactosidic linkages in agarose, yielding agarotetraose as the major product | ||||||||||||
Glossary: | agarose = a linear polysaccharide produced by some members of the Rhodophyta (red algae) made up from alternating D-galactose and 3,6-anhydro-α-L-galactopyranose residues joined by α-(1→3)- and β-(1→4)-linkages. In the field of oligosaccharides derived from agarose, carrageenans, etc., in which alternate residues are 3,6-anhydro sugars, the prefix ’neo’ designates an oligosaccharide whose non-reducing end is the anhydro sugar, and the absence of this prefix means that it is not. For example: neoagarobiose = 3,6-anhydro-α-L-galactopyranosyl-(1→3)-D-galactose agarobiose = β-D-galactopyranosyl-(1→4)-3,6-anhydro-L-galactose |
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Other name(s): | agarase (ambiguous); agaraseA33 | ||||||||||||
Systematic name: | agarose 3-glycanohydrolase | ||||||||||||
Comments: | Requires Ca2+. The enzyme from Thalassomonas sp. can use agarose, agarohexaose and neoagarohexaose as substrate. The products of agarohexaose hydrolysis are dimers and tetramers, with agarotetraose being the predominant product, whereas hydrolysis of neoagarohexaose gives rise to two types of trimer. While the enzyme can also hydrolyse the highly sulfated agarose porphyran very efficiently, it cannot hydrolyse the related compounds κ-carrageenan (see EC 3.2.1.83) and ι-carrageenan (see EC 3.2.1.157) [2]. See also EC 3.2.1.81, β-agarase. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number: 63952-00-1 | ||||||||||||
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EC | 3.2.1.159 | ||||||||||||
Accepted name: | α-neoagaro-oligosaccharide hydrolase | ||||||||||||
Reaction: | Hydrolysis of the (1→3)-α-L-galactosidic linkages of neoagaro-oligosaccharides that are smaller than a hexamer, yielding 3,6-anhydro-L-galactose and D-galactose | ||||||||||||
Glossary: | In the field of oligosaccharides derived from agarose, carrageenans, etc., in which alternate residues are 3,6-anhydro sugars, the prefix ’neo’ designates an oligosaccharide whose non-reducing end is the anhydro sugar, and the absence of this prefix means that it is not. For example: neoagarobiose = 3,6-anhydro-α-L-galactopyranosyl-(1→3)-D-galactose agarobiose = β-D-galactopyranosyl-(1→4)-3,6-anhydro-L-galactose |
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Other name(s): | α-neoagarooligosaccharide hydrolase; α-NAOS hydrolase | ||||||||||||
Systematic name: | α-neoagaro-oligosaccharide 3-glycohydrolase | ||||||||||||
Comments: | When neoagarohexaose is used as a substrate, the oligosaccharide is cleaved at the non-reducing end to produce 3,6-anhydro-L-galactose and agaropentaose, which is further hydrolysed to agarobiose and agarotriose. With neoagarotetraose as substrate, the products are predominantly agarotriose and 3,6-anhydro-L-galactose. In Vibrio sp. the actions of EC 3.2.1.81, β-agarase and EC 3.2.1.159 can be used to degrade agarose to 3,6-anhydro-L-galactose and D-galactose. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 60063-77-6 | ||||||||||||
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EC | 3.2.1.178 | ||||||||||||
Accepted name: | β-porphyranase | ||||||||||||
Reaction: | Hydrolysis of β-D-galactopyranose-(1→4)-α-L-galactopyranose-6-sulfate linkages in porphyran | ||||||||||||
Other name(s): | porphyranase; PorA; PorB; endo-β-porphyranase | ||||||||||||
Systematic name: | porphyran β-D-galactopyranose-(1→4)-α-L-galactopyranose-6-sulfate 4-glycanohydrolase | ||||||||||||
Comments: | The backbone of porphyran consists largely (~70%) of (1→3)-linked β-D-galactopyranose followed by (1→4)-linked α-L-galactopyranose-6-sulfate [the other 30% are mostly agarobiose repeating units of (1→3)-linked β-D-galactopyranose followed by (1→4)-linked 3,6-anhydro-α-L-galactopyranose] [2]. This enzyme cleaves the (1→4) linkages between β-D-galactopyranose and α-L-galactopyranose-6-sulfate, forming mostly the disaccharide α-L-galactopyranose-6-sulfate-(1→3)-β-D-galactose, although some longer oligosaccharides of even number of residues are also observed. Since the enzyme is inactive on the non-sulfated agarose portion of the porphyran backbone, some agarose fragments are also included in the products [1]. Methylation of the D-galactose prevents the enzyme from Zobellia galactanivorans, but not that from Wenyingzhuangia fucanilytica, from binding at subsite -1 [2,3]. | ||||||||||||
Links to other databases: | BRENDA, EXPASY, KEGG, MetaCyc, PDB | ||||||||||||
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