Cloned (Comment) | Organism |
---|---|
expressed in Escherichia coli | Pyrococcus sp. |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
Cd2+ | - |
Pyrococcus sp. | |
Cu2+ | - |
Pyrococcus sp. | |
maltose | competitive | Pyrococcus sp. |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
8.4 | - |
maltotriose | pH 5.0, 90°C | Pyrococcus sp. | |
18.8 | - |
maltotetraose | pH 5.0, 90°C | Pyrococcus sp. | |
21.2 | - |
maltopentaose | pH 5.0, 90°C | Pyrococcus sp. |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
70000 | - |
4 * 70000, SDS-PAGE | Pyrococcus sp. |
70191 | - |
4 * 70191, calculated from sequence | Pyrococcus sp. |
260000 | - |
gel filtration | Pyrococcus sp. |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Pyrococcus sp. | I3RE04 | - |
- |
Pyrococcus sp. ST04 | I3RE04 | - |
- |
Purification (Comment) | Organism |
---|---|
- |
Pyrococcus sp. |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
1.25 | - |
pH 5.0, 90°C, substrate: maltotriose | Pyrococcus sp. |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
4-nitrophenyl alpha-D-maltohexaoside + H2O | - |
Pyrococcus sp. | 4-nitrophenol + maltohexaose | - |
? | |
amylopectin + H2O | the enzyme recognized maltose units with alpha-1,4 and alpha-1,6 linkages in polysaccharides (e.g., starch, amylopectin, and glycogen) and hydrolyzes pullulan very poorly. Branched cyclodextrin is only hydrolyzed along its branched maltooligosaccharides. 6-O-D-glucosyl-beta-cyclodextrin and beta-cyclodextrin are resistant. Exo-type glucan hydrolase with alpha-1,4- and alpha-1,6-glucan hydrolytic activities | Pyrococcus sp. | maltose + ? | maltose is the primary end product of hydrolysis | ? | |
amylopectin + H2O | the enzyme recognized maltose units with alpha-1,4 and alpha-1,6 linkages in polysaccharides (e.g., starch, amylopectin, and glycogen) and hydrolyzes pullulan very poorly. Branched cyclodextrin is only hydrolyzed along its branched maltooligosaccharides. 6-O-D-glucosyl-beta-cyclodextrin and beta-cyclodextrin are resistant. Exo-type glucan hydrolase with alpha-1,4- and alpha-1,6-glucan hydrolytic activities | Pyrococcus sp. ST04 | maltose + ? | maltose is the primary end product of hydrolysis | ? | |
glycogen + H2O | the enzyme recognized maltose units with alpha-1,4 and alpha-1,6 linkages in polysaccharides (e.g., starch, amylopectin, and glycogen) and hydrolyzes pullulan very poorly. Branched cyclodextrin is only hydrolyzed along its branched maltooligosaccharides. 6-O-D-glucosyl-beta-cyclodextrin and beta-cyclodextrin are resistant.Exo-type glucan hydrolase with alpha-1,4- and alpha-1,6-glucan hydrolytic activities | Pyrococcus sp. | maltose + ? | maltose is the primary end product of hydrolysis | ? | |
maltopentaose + H2O | - |
Pyrococcus sp. | maltose + D-glucose + ? | - |
? | |
maltotetraose + H2O | - |
Pyrococcus sp. | 2 maltose | - |
? | |
maltotetraose + H2O | - |
Pyrococcus sp. ST04 | 2 maltose | - |
? | |
maltotriose + H2O | highest hydrolysis activities are on the alpha-1,4-glycosidic linkage of maltotriose (1.25 U/mg) and the alpha-1,6-glycosidic bond of 6-O-maltosyl-beta-cyclodextrin | Pyrococcus sp. | maltose + D-glucose | - |
? | |
maltotriose + H2O | highest hydrolysis activities are on the alpha-1,4-glycosidic linkage of maltotriose (1.25 U/mg) and the alpha-1,6-glycosidic bond of 6-O-maltosyl-beta-cyclodextrin | Pyrococcus sp. ST04 | maltose + D-glucose | - |
? | |
additional information | an exo-type maltose-forming alpha-amylase acting on the non-reducing end of the substrates and requires at least a G2 unit at its working sites of substrates. When the length of the branch is longer than G2 in the substrate, the enzyme primarily attacks alpha-1,4-glycosidic linkages in the long branch and cleaves off G2 unit until it reaches the final G2, and then it performs a debranching reaction by acting on alpha-1,6-glycosidic bonds at branching points | Pyrococcus sp. | ? | - |
? | |
additional information | an exo-type maltose-forming alpha-amylase acting on the non-reducing end of the substrates and requires at least a G2 unit at its working sites of substrates. When the length of the branch is longer than G2 in the substrate, the enzyme primarily attacks alpha-1,4-glycosidic linkages in the long branch and cleaves off G2 unit until it reaches the final G2, and then it performs a debranching reaction by acting on alpha-1,6-glycosidic bonds at branching points | Pyrococcus sp. ST04 | ? | - |
? | |
starch + H2O | the enzyme recognized maltose units with alpha-1,4 and alpha-1,6 linkages in polysaccharides (e.g., starch, amylopectin, and glycogen) and hydrolyzes pullulan very poorly. Branched cyclodextrin is only hydrolyzed along its branched maltooligosaccharides. 6-O-D-glucosyl-beta-cyclodextrin and beta-cyclodextrin are resistant.Exo-type glucan hydrolase with alpha-1,4- and alpha-1,6-glucan hydrolytic activities | Pyrococcus sp. | maltose + ? | maltose is the primary end product of hydrolysis | ? | |
starch + H2O | the enzyme recognized maltose units with alpha-1,4 and alpha-1,6 linkages in polysaccharides (e.g., starch, amylopectin, and glycogen) and hydrolyzes pullulan very poorly. Branched cyclodextrin is only hydrolyzed along its branched maltooligosaccharides. 6-O-D-glucosyl-beta-cyclodextrin and beta-cyclodextrin are resistant.Exo-type glucan hydrolase with alpha-1,4- and alpha-1,6-glucan hydrolytic activities | Pyrococcus sp. ST04 | maltose + ? | maltose is the primary end product of hydrolysis | ? |
Subunits | Comment | Organism |
---|---|---|
homotetramer | 4 * 70000, SDS-PAGE | Pyrococcus sp. |
homotetramer | 4 * 70191, calculated from sequence | Pyrococcus sp. |
Synonyms | Comment | Organism |
---|---|---|
PSMA | Pyrococcus sp. ST04 maltose-forming alpha-amylase | Pyrococcus sp. |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
90 | 95 | - |
Pyrococcus sp. |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
75 | - |
half-life: 254 min | Pyrococcus sp. |
85 | - |
half-life: 72 min | Pyrococcus sp. |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.0017 | - |
maltopentaose | pH 5.0, 90°C | Pyrococcus sp. | |
0.0033 | - |
maltotetraose | pH 5.0, 90°C | Pyrococcus sp. | |
6.35 | - |
maltotriose | pH 5.0, 90°C | Pyrococcus sp. |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
5 | - |
substrate: maltotriose | Pyrococcus sp. |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
4 | 6 | pH 4.0: less than 10% of maximal activity, pH 6.0: about 40% of maximal activity | Pyrococcus sp. |
Ki Value [mM] | Ki Value maximum [mM] | Inhibitor | Comment | Organism | Structure |
---|---|---|---|---|---|
0.7 | - |
maltose | pH 5.0, 90°C | Pyrococcus sp. |
General Information | Comment | Organism |
---|---|---|
physiological function | the enzyme may have a role in regulating the concentration of maltose during maltodextrin metabolism | Pyrococcus sp. |
kcat/KM Value [1/mMs-1] | kcat/KM Value Maximum [1/mMs-1] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.000078 | - |
maltopentaose | pH 5.0, 90°C | Pyrococcus sp. | |
0.000193 | - |
maltotetraose | pH 5.0, 90°C | Pyrococcus sp. | |
0.76 | - |
maltotriose | pH 5.0, 90°C | Pyrococcus sp. |