General Stability | Organism |
---|---|
partially purified esterase (from second ion exchange chromatography) resistant to freezing-thawing cycles, presence of beta-mercaptoethanol during purification preserves enzyme activity | Equus sp. |
Inhibitors | Comment | Organism | Structure |
---|---|---|---|
diisopropylfluorophosphate | 1 mM, 25°C, 15 min, total loss of activity | Equus sp. | |
additional information | bis-(4-nitrophenyl)phosphate, 1 mM Ca2+, 1 mM ethylene diaminotetraacetate (EDTA) without influence on activity | Equus sp. | |
paraoxon | diethyl-4-nitrohenylphosphate (E600), 1 mM at 25°C within 15 min leads to total loss of activity | Equus sp. |
KM Value [mM] | KM Value Maximum [mM] | Substrate | Comment | Organism | Structure |
---|---|---|---|---|---|
0.3 | - |
4-O-acetyl-sialic acid | low pI esterase form, obtained with free sialic acid | Equus sp. | |
1.1 | - |
9-O-acetyl-sialic acid | low pI esterase form, obtained with free sialic acid | Equus sp. | |
1.3 | - |
9-O-acetyl-sialic acid | high pI esterase form, obtained with free sialic acid | Equus sp. |
Metals/Ions | Comment | Organism | Structure |
---|---|---|---|
Cu2+ | 1 mM, block of essential SH-groups | Equus sp. | |
Hg2+ | 1 mM, block of essential SH-groups | Equus sp. | |
Zn2+ | 1 mM, block of essential SH-groups | Equus sp. |
Molecular Weight [Da] | Molecular Weight Maximum [Da] | Comment | Organism |
---|---|---|---|
54000 | - |
gel-filtration | Equus sp. |
Organism | UniProt | Comment | Textmining |
---|---|---|---|
Equus sp. | - |
- |
- |
Oxidation Stability | Organism |
---|---|
15 min incubation with 1 mM 4-hydroxymercuribenzoate at 25°C leads to total loss of activity | Equus sp. |
Purification (Comment) | Organism |
---|---|
from fresh tissue by ultracentrifugation (dialysis of supernatant), followed by gel-filtration on Sephadex G-200 column, ion-exchange chromatography on Sephadex-DEAE-A-50 column, second ion-exchange chromatography on DEAE-Sephacel column, isoelectric focussing on ampholine of pH 3.5-9.5 and a saccharose gradient, and final dialysis, 866% purification compared to homogenate | Equus sp. |
Source Tissue | Comment | Organism | Textmining |
---|---|---|---|
liver | - |
Equus sp. | - |
Specific Activity Minimum [µmol/min/mg] | Specific Activity Maximum [µmol/min/mg] | Comment | Organism |
---|---|---|---|
0.00012 | - |
homogenate | Equus sp. |
0.104 | - |
after preparative isoelectric focussing, pI 4.8 | Equus sp. |
Storage Stability | Organism |
---|---|
-20°C, after preparative isoelectric focusing, few weeks, total loss of activity, -70°C, frozen liver, stable for 1-2 years | Equus sp. |
Substrates | Comment Substrates | Organism | Products | Comment (Products) | Rev. | Reac. |
---|---|---|---|---|---|---|
4-O-acetyl sialic acid + H2O | - |
Equus sp. | sialic acid + acetate | - |
? | |
9-O-acetyl sialic acid + H2O | - |
Equus sp. | sialic acid + acetate | - |
? | |
additional information | alpha-naphthylacetate, 9-O-acetyl sialyllactose, serum alpha1 acid glycoprotein, and erythrocyte membranes containing N-acetyl-4-O-acetylneuraminic acid or N-acetyl-9-O-acetylneuraminic acid are susceptible to SOAE catalysed hydrolysis | Equus sp. | ? | - |
? | |
additional information | glycosidically linked sialic acids are also substrate, hydrolysis of 20% under standard conditions | Equus sp. | ? | - |
? | |
additional information | liberation of sialic acid from gland mucin (mainly containing N-acetyl-4-O-acetylneuraminic acid) | Equus sp. | ? | - |
? | |
additional information | N-acetyl-4-O-acetylneuraminic acid is slightly preferred over N-acetyl-9-O-acetylneuraminic acid as substrate for esterase with pI 5.7 | Equus sp. | ? | - |
? | |
additional information | N-acetyl-7-O-acetylneuraminic acid is no substrate | Equus sp. | ? | - |
? | |
N-acetyl-4-O-acetylneuraminic acid + H2O | pH 8, 30 min, 37°C, catalysed only by esterase with pI 5.7 | Equus sp. | N-acetylneuraminate + acetate | analyses by HPLC | ? | |
N-acetyl-9-O-acetylneuraminic acid + H2O | pH 8, 30 min, 37°C, catalysed by esterase with pI 4.8 and esterase with pI 5.7 | Equus sp. | N-acetylneuraminate + acetate | analyses by HPLC | ? |
Synonyms | Comment | Organism |
---|---|---|
sialate esterase | - |
Equus sp. |
sialate-O-acetylesterase | - |
Equus sp. |
SOAE | - |
Equus sp. |
pH Optimum Minimum | pH Optimum Maximum | Comment | Organism |
---|---|---|---|
8.4 | 8.6 | - |
Equus sp. |
pH Minimum | pH Maximum | Comment | Organism |
---|---|---|---|
7 | - |
60% lower activity compared to optimum | Equus sp. |
Organism | Comment | pI Value Maximum | pI Value |
---|---|---|---|
Equus sp. | isoelectric focusing, low pI form | - |
4.8 |
Equus sp. | isoelectric focusing, high pI form | - |
5.7 |