Activating Compound | Comment | Organism | Structure |
---|---|---|---|
Glucan | stimulates the isoform SSIIa and SSIII reaction rates | Zea mays |
Cloned (Comment) | Organism |
---|---|
expressed in Escherichia coli Rosetta2 (DE3) pLysS cells | Zea mays |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.33 | - |
ADP-alpha-D-glucose | free isoform SSIII, at pH 8.0 and 30°C | Zea mays | |
0.39 | - |
ADP-alpha-D-glucose | free isoform SSI, at pH 8.0 and 30°C | Zea mays | |
0.84 | - |
ADP-alpha-D-glucose | free isoform SSIIa, at pH 8.0 and 30°C | Zea mays |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
70000 | - |
x * 70000, isoform SSI, calculated from amino acid sequence | Zea mays |
77000 | - |
x * 77000, isoform SSIIa, calculated from amino acid sequence | Zea mays |
180000 | - |
x * 180000, isoform SSIII, calculated from amino acid sequence | Zea mays |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Zea mays | - |
- |
- |
Purification (Comment) | Organism |
---|---|
Ni-NTA agarose column chromatography, and gel filtration | Zea mays |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
6.16 | - |
free isoform SSI, at pH 8.0 and 30°C | Zea mays |
6.33 | - |
free isoform SSIII, at pH 8.0 and 30°C | Zea mays |
9.75 | - |
free isoform SSIIa, at pH 8.0 and 30°C | Zea mays |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
ADP-alpha-D-glucose + glycogen | - |
Zea mays | ADP + ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
? | x * 180000, isoform SSIII, calculated from amino acid sequence | Zea mays |
? | x * 70000, isoform SSI, calculated from amino acid sequence | Zea mays |
? | x * 77000, isoform SSIIa, calculated from amino acid sequence | Zea mays |
Synonyms | Comment | Organism |
---|---|---|
SSI | isoform | Zea mays |
SSIIa | isoform | Zea mays |
SSIII | isoform | Zea mays |
starch synthase | - |
Zea mays |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
37 | 50 | pre-incubation at up to 45°C has no effect on the activity of isoform SSI. Isoform SSIIa is stimulated by preincubation at 37-45°C, while isoform SSIII activity is reduced by ca. 50% after brief incubation at 45°C. Isoform SSIII is stable during preincubation at 37°C. At 50°C all enzymes completely lose activity within 40 min | Zea mays |