Activating Compound | Comment | Organism | Structure |
---|---|---|---|
L-lysine | excess lysine is a major stimulator of enzyme activity | Nicotiana tabacum | |
organic solvent | activates | Zea mays | |
organic solvent | e.g. poly(ethylene glycol) 8000 and ethyleneglycol increase enzyme activity, but lower increase than by 200 mM Tris/HCl buffer | Zea mays | |
Tris/HCl | enzyme activity increases 6fold when the concentration of Tris/HCl is increased from 25 to 200 mM, effect is due to decreased water activity which could induce conformational modification in LOR domain of enzyme | Zea mays |
Protein Variants | Comment | Organism |
---|---|---|
additional information | - |
Saccharomyces cerevisiae |
additional information | in endosperm of opaque-2 mutant level of enzyme activity is reduced 2-3fold compared to normal endosperm | Zea mays |
General Stability | Organism |
---|---|
stabilization of holoenzyme by high salt concentrations, e.g. KCl | Zea mays |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
Calmidazolium | 0.04 mM, almost complete inhibition of Ca2+-dependent enhancement of enzyme activity, calmodulin antagonist | Zea mays | |
EGTA | 1.6 mM, 70% loss of activity in crude extract, activity can be restored by addition of 1.6 mM CaCl2 | Zea mays | |
additional information | lysine-oxoglutarate reductase shows time-dependent and protease-concentration-dependent inactivation by proteolysis followed by reactivation, saccharopine dehydrogenase-containing polypeptides obtained by prolonged digestion inhibit the activity of lysine-oxoglutarate reductase-containing polypeptides | Zea mays | |
N-(6-Aminohexyl)-5-chloro-1-naphthalenesulfonamide | 1.5 mM, almost complete inhibition of Ca2+-dependent enhancement of enzyme activity, calmodulin antagonist | Zea mays |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Ca2+ | activates separated lysine-oxoglutarate reductase domain and this domain in bifunctional protein, Ca2+ may be the most important physiological modulator of enzyme activity, it possibly activates through the derepression of an inhibitory domain in vivo | Zea mays | |
Mg2+ | activates at millimolar concentrations | Zea mays | |
Salt | e.g. NaCl or KCl, high salt concentrations activate bifunctional enzyme, but not separated lysine-oxoglutarate reductase domain, 15fold increase of enzyme activity when salt concentration is increased from 0 to 200 mM, effect is due to decreased water activity which could induce conformational modification in LOR domain of enzyme or activation may result from stabilizing effect of the dimeric form of enzyme | Zea mays |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
125000 | - |
2 * 125000, bifunctional enzyme with lysine-oxoglutarate reductase EC 1.5.1.8 and saccharopine dehydrogenase EC 1.5.1.9 activities, digestion with elastase separates the functional domains into a 65 kDa polypeptide with LOR activity and a 57 kDa polypeptide with SDH activity, SDS-PAGE | Zea mays |
260000 | - |
bifunctional enzyme with lysine-oxoglutarate reductase EC 1.5.1.8 and saccharopine dehydrogenase EC 1.5.1.9 activities, but domains are functionally independent of each other | Zea mays |
Natural Substrates | Organism | Comment (Nat. Sub.) | Natural Products | Comment (Nat. Pro.) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-lysine + 2-oxoglutarate + NADPH | Saccharomyces cerevisiae | biosynthetic pathway of lysine in yeast and fungi | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? | |
L-lysine + 2-oxoglutarate + NADPH | Zea mays | activity of native enzyme is inhibited after modulation, enzyme undergoes a conformational alteration to expose the catalytic domain for substrate binding, Ca2+ may be the most important physiological modulator of enzyme activity, it possibly activates through the derepression of an inhibitory domain in vivo | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? | |
L-lysine + 2-oxoglutarate + NADPH | Saccharomyces cerevisiae | increase in free lysine concentration in cells decrease enzyme activity through repression of lys1 gene, precursor alpha-aminoadipic-delta-semialdehyde modulates a transcriptional factor that controls transcription of lys1 gene | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? | |
L-lysine + 2-oxoglutarate + NADPH | Zea mays | lysine catabolism | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? | |
L-lysine + 2-oxoglutarate + NADPH | Nicotiana tabacum | enzyme activity is modulated in vivo by a lysine-dependent intracellular signaling cascade, mediated by Ca2+ and protein phosphorylation/dephosphorylation | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Nicotiana tabacum | - |
- |
- |
Saccharomyces cerevisiae | - |
- |
- |
Zea mays | - |
hybrid F-352 | - |
Purification (Comment) | Organism |
---|---|
partial purification of bifunctional enzyme with lysine-oxoglutarate reductase EC 1.5.1.8 and saccharopine dehydrogenase EC 1.5.1.9 activities | Zea mays |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
endosperm | during development | Zea mays | - |
seed | developing | Zea mays | - |
seed | developing | Nicotiana tabacum | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
additional information | - |
- |
Zea mays |
1.273 | - |
- |
Zea mays |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
L-lysine + 2-oxoglutarate + NADPH | - |
Saccharomyces cerevisiae | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | N6-(L-1,3-dicarboxypropyl)-L-lysine is identical with saccharopine | ? | |
L-lysine + 2-oxoglutarate + NADPH | enzyme catalyzes lysine degradation to saccharopine | Zea mays | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | N6-(L-1,3-dicarboxypropyl)-L-lysine is identical with saccharopine | ? | |
L-lysine + 2-oxoglutarate + NADPH | enzyme catalyzes lysine degradation to saccharopine | Nicotiana tabacum | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | N6-(L-1,3-dicarboxypropyl)-L-lysine is identical with saccharopine | ? | |
L-lysine + 2-oxoglutarate + NADPH | biosynthetic pathway of lysine in yeast and fungi | Saccharomyces cerevisiae | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? | |
L-lysine + 2-oxoglutarate + NADPH | activity of native enzyme is inhibited after modulation, enzyme undergoes a conformational alteration to expose the catalytic domain for substrate binding, Ca2+ may be the most important physiological modulator of enzyme activity, it possibly activates through the derepression of an inhibitory domain in vivo | Zea mays | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? | |
L-lysine + 2-oxoglutarate + NADPH | increase in free lysine concentration in cells decrease enzyme activity through repression of lys1 gene, precursor alpha-aminoadipic-delta-semialdehyde modulates a transcriptional factor that controls transcription of lys1 gene | Saccharomyces cerevisiae | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? | |
L-lysine + 2-oxoglutarate + NADPH | lysine catabolism | Zea mays | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? | |
L-lysine + 2-oxoglutarate + NADPH | enzyme activity is modulated in vivo by a lysine-dependent intracellular signaling cascade, mediated by Ca2+ and protein phosphorylation/dephosphorylation | Nicotiana tabacum | N6-(L-1,3-dicarboxypropyl)-L-lysine + NADP+ + H2O | - |
? | |
additional information | bifunctional enzyme with lysine-oxoglutarate reductase EC 1.5.1.8 and saccharopine dehydrogenase EC 1.5.1.9 activities | Zea mays | ? | - |
? |
Subunits | Comment | Organism |
---|---|---|
homodimer | 2 * 125000, bifunctional enzyme with lysine-oxoglutarate reductase EC 1.5.1.8 and saccharopine dehydrogenase EC 1.5.1.9 activities, digestion with elastase separates the functional domains into a 65 kDa polypeptide with LOR activity and a 57 kDa polypeptide with SDH activity, SDS-PAGE | Zea mays |
Temperature Optimum [°C] | Temperature Optimum Maximum [°C] | Comment | Organism |
---|---|---|---|
30 | - |
assay at | Zea mays |
Cofactor | Comment | Organism | Structure |
---|---|---|---|
NADPH | - |
Zea mays | |
NADPH | - |
Nicotiana tabacum |