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Literature summary for 5.1.3.37 extracted from
- Overall size of mannuronan C5-epimerases influences their ability to epimerize modified alginates and alginate gels (2018), Carbohydr. Polym., 180, 256-263 .
Cloned(Commentary)
| Cloned (Comment) | Organism |
|---|---|
| recombinant His-tagged enzyme expression in Escherichia coli strain BL21(DE3), subcloning in Escherichia coli strain DH5alpha | Azotobacter vinelandii |
Protein Variants
| Protein Variants | Comment | Organism |
|---|---|---|
| additional information | mannuronan C5-epimerases (AlgE1-AlgE7) produced by Azotobacter vinelandii are able to convert beta-D-mannuronate to its epimer alpha-L-guluronate in alginates. The introduction of new G-blocks into the polymer by in vitro epimerization is a strategy to improve the mechanical properties of alginates as biomaterial. Epimerization is hampered when the substrate is modified or in the gelled state. Reducing the size of the epimerases enables the epimerization of otherwise inaccessible regions in the alginate polymer. Even though the reduction of the size affects the productive binding of epimerases to the substrate, and hence their activity, the smaller epimerases can more freely diffuse into calcium-alginate hydrogel and epimerize it | Azotobacter vinelandii |
| additional information | mannuronan C5-epimerases (AlgE1-AlgE7) produced by Azotobacter vinelandii are able to convert beta-D-mannuronate to its epimer alpha-L-guluronate in alginates. The introduction of new G-blocks into the polymer by in vitro epimerization is a strategy to improve the mechanical properties of alginates as biomaterial. Epimerization is hampered when the substrate is modified or in the gelled state. Reducing the size of the epimerases enables the epimerization of otherwise inaccessible regions in the alginate polymer. Even though the reduction of the size affects the productive binding of epimerases to the substrate, and hence their activity, the smaller epimerases can more freely diffuse into calcium-alginate hydrogel and epimerize it. Construction of thehybrid enzyme AlgE6A with A-module, and the hybrid enzyme AlgE64 constituted by the Amodule from AlgE6 and the R-module from AlgE4, modular structure, overview. The A-module is the minimal size for an active epimerase, even though the active site is located in proximity of the N-terminus. Reducing the size of AlgE6 influences the epimerization of modified alginates in solution | Azotobacter vinelandii |
| additional information | mannuronan C5-epimerases (AlgE1-AlgE7) produced by Azotobacter vinelandii are able to convert beta-D-mannuronate to its epimer alpha-L-guluronate in alginates. The introduction of new G-blocks into the polymer by in vitro epimerization is a strategy to improve the mechanical properties of alginates as biomaterial. Epimerization is hampered when the substrate is modified or in the gelled state. Reducing the size of the epimerases enables the epimerization of otherwise inaccessible regions in the alginate polymer. Even though the reduction of the size affects the productive binding of epimerases to the substrate, and hence their activity, the smaller epimerases can more freely diffuse into calcium-alginate hydrogel and epimerize it. Enzyme modular structure, overview | Azotobacter vinelandii |
Metals/Ions
| Metals/Ions | Comment | Organism | Structure |
|---|---|---|---|
| Ca2+ | required for activity, all the mannuronan C5-epimerases of Azotobacter vinelandii show differences in concentration of calcium ions needed for full activity, overview | Azotobacter vinelandii |  |
Natural Substrates/ Products (Substrates)
| Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| [mannuronan]-beta-D-mannuronate | Azotobacter vinelandii | - |
[alginate]-alpha-L-guluronate | - |
r | |
Organism
| Organism | UniProt | Comment | Textmining |
|---|---|---|---|
| Azotobacter vinelandii | Q44492 | - |
- |
| Azotobacter vinelandii | Q44493 | - |
- |
| Azotobacter vinelandii | Q44494 | - |
- |
| Azotobacter vinelandii | Q44495 | - |
- |
| Azotobacter vinelandii | Q44496 | - |
- |
| Azotobacter vinelandii | Q9ZFG9 | - |
- |
| Azotobacter vinelandii | Q9ZFH0 | - |
- |
Purification (Commentary)
| Purification (Comment) | Organism |
|---|---|
| recombinant His-tagged enzyme from Escherichia coli strain BL21(DE3) by gel filtration, nickel affinity and chitin affinity chromatography | Azotobacter vinelandii |
Substrates and Products (Substrate)
| Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
|---|---|---|---|---|---|---|
| additional information | all the mannuronan C5-epimerases of Azotobacter vinelandii show differences in substrate specificity and concentration of calcium ions needed for full activity | Azotobacter vinelandii | ? | - |
? | |
| additional information | all the mannuronan C5-epimerases of Azotobacter vinelandii show differences in substrate specificity and concentration of calcium ions needed for full activity. AlgE4 acts processively by sliding along the alginate chain and epimerizing every second residue, generating alternating MG-sequences. Epimerization of calcium-alginate gel beads and of oxidized/reduced polyM and acetylated alginate by recombinant enzyme, overview. The enzyme is tested on internally gelled high-M calcium-alginate cylinders | Azotobacter vinelandii | ? | - |
? | |
| additional information | all the mannuronan C5-epimerases of Azotobacter vinelandii show differences in substrate specificity and concentration of calcium ions needed for full activity. Epimerization of calcium-alginate gel beads and of oxidized/reduced polyM and acetylated alginate by recombinant enzyme, overview. The enzyme is tested on internally gelled high-M calcium-alginate cylinders, AlgE6 and AlgE64 show a gradient in the G-content which decreases from the outer wall towards the core of the cylinder, while AlgE6A gives the same degree of epimerization across the whole gel cylinder. GG-dyads content also follows the same trend | Azotobacter vinelandii | ? | - |
? | |
| additional information | all the mannuronan C5-epimerases of Azotobacter vinelandii show differences in substrate specificity and concentration of calcium ions needed for full activity. Epimerization of calcium-alginate gel beads and of oxidized/reduced polyM and acetylated alginate by recombinant enzyme, overview. The enzyme is tested on internally gelled high-M calcium-alginate cylinders: AlgE1 shows a gradient in the G-content which decreases from the outer wall towards the core of the cylinder. GG-dyads content also follows the same trend | Azotobacter vinelandii | ? | - |
? | |
| [mannuronan]-beta-D-mannuronate | - |
Azotobacter vinelandii | [alginate]-alpha-L-guluronate | - |
r | |
Synonyms
| Synonyms | Comment | Organism |
|---|---|---|
| AlgE1 | - |
Azotobacter vinelandii |
| AlgE2 | - |
Azotobacter vinelandii |
| AlgE3 | - |
Azotobacter vinelandii |
| AlgE4 | - |
Azotobacter vinelandii |
| AlgE5 | - |
Azotobacter vinelandii |
| AlgE6 | - |
Azotobacter vinelandii |
| AlgE7 | - |
Azotobacter vinelandii |
| mannuronan C5-epimerase | - |
Azotobacter vinelandii |
Temperature Optimum [°C]
| Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
|---|---|---|---|
| 37 | - |
assay at | Azotobacter vinelandii |
pH Optimum
| pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
|---|---|---|---|
| 6.9 | - |
assay at | Azotobacter vinelandii |
General Information
| General Information | Comment | Organism |
|---|---|---|
| malfunction | reducing the size of AlgE6 influences the epimerization of modified alginates in solution. The A-module from AlgE6 seems to be more affected than AlgE64 at higher degree of oxidation | Azotobacter vinelandii |
| additional information | the A-module is the minimal size for an active epimerase even though the active site is located in proximity of the N-terminus | Azotobacter vinelandii |
| additional information | the A-module is the minimal size for an active epimerase even though the active site is located in proximity of the N-terminus. AlgE1 is larger than AlgE6 and has two catalytic active modules (A1 and A2) | Azotobacter vinelandii |
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