Cloned (Comment) | Organism |
---|---|
expressed in Escherichia coli, plasmid pET/codA1 | Arthrobacter globiformis |
General Stability | Organism |
---|---|
storage at -20°C and pH 6 results in a change in the conformation, loss of catalytic activity at pH 6, reactivation of the enzyme slow at pH 6 and temperatures between 20 and 39°C, facilitated by elevated pH values at 25°C and pH above 6.5 | Arthrobacter globiformis |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.5 | - |
choline | previously stored at pH 6 and 0°C, measured at pH 7 and 25°C | Arthrobacter globiformis | |
0.6 | - |
choline | previously stored at pH 8 and -20°C, measured at pH 7 and 25°C | Arthrobacter globiformis | |
0.6 | - |
choline | previously stored at pH 8 and 0°C, measured at pH 7 and 25°C | Arthrobacter globiformis | |
0.7 | - |
choline | previously stored at pH 6 and -20°C, measured at pH 7 and 25°C | Arthrobacter globiformis |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
choline + O2 | Arthrobacter globiformis | - |
betaine aldehyde + H2O2 | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Arthrobacter globiformis | Q7X2H8 | strain ATCC 8010 | - |
Purification (Comment) | Organism |
---|---|
recombinant protein, purified to homogeneity, gel filtration | Arthrobacter globiformis |
Renatured (Comment) | Organism |
---|---|
conformational change reverting the enzyme to the native form, rate of approaching steady state independent of concentrations of choline and enzyme, increased to a limiting value with increasing pH | Arthrobacter globiformis |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
commercial preparation | - |
Arthrobacter globiformis | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
temperature effects on the apparent rate constant for slow transition from inactive to active form, pH effects on the hysteretic behavior, effect of storage pH and temperature on activity | Arthrobacter globiformis |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
choline + O2 | - |
Arthrobacter globiformis | betaine aldehyde + H2O2 | - |
? | |
choline + O2 | localized structural changes trap choline oxidase in a nonfunctional folded conformation, reversible loss of ability to catalyze the oxidation of choline | Arthrobacter globiformis | betaine aldehyde + H2O2 | - |
? |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
25 | - |
time courses of oxygen consumption and enzymatic activity, incubation of the inactive enzyme at 25°C above pH 6.5 reveals fast and partial reactivation, slow onset of steady state during enzymatic turnover | Arthrobacter globiformis |
Temperature Minimum [°C] | Temperature Maximum [°C] | Comment | Organism |
---|---|---|---|
20 | 39 | effect of temperature on the rate of reactivation at pH 6 | Arthrobacter globiformis |
Temperature Stability Minimum [°C] | Temperature Stability Maximum [°C] | Comment | Organism |
---|---|---|---|
additional information | - |
freezing at low pH leads to reversible conformational change, associated with complete and reversible loss of catalytic activity | Arthrobacter globiformis |
Turnover Number Minimum [1/s] | Turnover Number Maximum [1/s] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
4.4 | - |
choline | previously stored at pH 6 and -20°C, measured at pH 7 and 25°C | Arthrobacter globiformis | |
13.3 | - |
choline | previously stored at pH 6 and 0°C, measured at pH 7 and 25°C | Arthrobacter globiformis | |
14.9 | - |
choline | previously stored at pH 8 and 0°C, measured at pH 7 and 25°C | Arthrobacter globiformis | |
15.5 | - |
choline | previously stored at pH 8 and -20°C, measured at pH 7 and 25°C | Arthrobacter globiformis |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
7 | - |
activity assay at | Arthrobacter globiformis |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
6.5 | 9.6 | pH effects on the rate constants for fast transition from inactive to active form measured, choline concentrations in the range from 0.1 to 10 mM, temperature effects on enzyme reactivation determined at pH 6 | Arthrobacter globiformis |
pH Stability | pH Stability Maximum | Comment | Organism |
---|---|---|---|
additional information | - |
prolonged incubation of the inactive enzyme at pH 6 and temperatures above 20°C reveals slow and full recovery of activity over 3 hours, linked to conformational change reverting the enzyme to the native form, rate of approaching steady state independent of concentrations of choline and enzyme, increased to a limiting value with increasing pH | Arthrobacter globiformis |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
FAD | groups responsible for the change in the protein conformation are not likely to be in the enzyme active site, direct effect on the microenvironment of the enzyme-bound flavin and activity of the enzyme | Arthrobacter globiformis |