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Literature summary for 4.2.1.123 extracted from

  • Saar, J.; Kader, J.; Poralla, K.; Ourisson, G.
    Purification and some properties of the squalene-tetrahymanol cyclase from Tetrahymena thermophila (1991), Biochim. Biophys. Acta, 1075, 93-101.
    View publication on PubMed

Inhibitors

Inhibitors Comment Organism Structure
2,3-iminosqualene effective inhibitor, complete inhibition at 1 mM Tetrahymena thermophila
4,4,10beta-trimethyltransdecal-3beta-ol 25% inhibition at 40 mM Tetrahymena thermophila
4-chloromercuribenzenesulfonic acid 86% inhibition at 5 mM Tetrahymena thermophila
diethyldicarbonate complete inhibition at 5 mM Tetrahymena thermophila
Digitonin solubilization of the cyclase in 8 mg/ml digitonin inactivates the enzyme, its activity can be recovered by complementation of the assay buffer with octylthioglucoside above its critical micellar concentration Tetrahymena thermophila
Emulgene 911 solubilization of the cyclase in 1 mg/ml Emulgene 911 inactivates the enzyme Tetrahymena thermophila
additional information the cyclase is not influenced by EDTA concentrations up to 0.1 M, and lodoacetate is not inhibitory at 1 and 5 mM Tetrahymena thermophila
N,N-Dimethyldodecylamine-N-oxide effective inhibitor, complete inhibition at 1 mM Tetrahymena thermophila
Ro 43-8522 effective inhibitor, complete inhibition at 1 mM Tetrahymena thermophila
Triton X-100 strong inactivator Tetrahymena thermophila
Tween 80 solubilization of the cyclase in 30 mg/ml Tween 80 inactivates the enzyme, its activity can be recovered by complementation of the assay buffer with octylthioglucoside above its critical micellar concentration Tetrahymena thermophila

Localization

Localization Comment Organism GeneOntology No. Textmining
membrane
-
Tetrahymena thermophila 16020
-

Molecular Weight [Da]

Molecular Weight [Da] Molecular Weight Maximum [Da] Comment Organism
72000
-
SDS-PAGE Tetrahymena thermophila

Organic Solvent Stability

Organic Solvent Comment Organism
CHAPS CHAPS effectively solubilizes the enzyme and maintains its activity Tetrahymena thermophila

Organism

Organism UniProt Comment Textmining
Tetrahymena thermophila
-
-
-
Tetrahymena thermophila B4-1868 (ATCC 30382)
-
-
-

Purification (Commentary)

Purification (Comment) Organism
DEAE-trisacryl column chromatography, hydroxyapatite column chromatography, and Mono Q column chromatography Tetrahymena thermophila

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
105
-
enzyme from homogenate, pH 7.0, 30°C Tetrahymena thermophila
31280
-
enzyme after 297fold purification, pH 7.0, 30°C Tetrahymena thermophila

Storage Stability

Storage Stability Organism
-80°C, whole cells and particulate material, 6 months, no loss of activity Tetrahymena thermophila
6°C, octylthioglucoside-solubilized enzyme, one week, almost complete loss of activity Tetrahymena thermophila

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
2 squalene + 2 H2O
-
Tetrahymena thermophila tetrahymanol + diplopterol diplopterol amounts to less than 2% of the total products formed by enzymatic conversion ?
2 squalene + 2 H2O
-
Tetrahymena thermophila B4-1868 (ATCC 30382) tetrahymanol + diplopterol diplopterol amounts to less than 2% of the total products formed by enzymatic conversion ?

Synonyms

Synonyms Comment Organism
squalene-tetrahymanol cyclase
-
Tetrahymena thermophila

Temperature Optimum [°C]

Temperature Optimum [°C] Temperature Optimum Maximum [°C] Comment Organism
30
-
-
Tetrahymena thermophila

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
50
-
the enzyme is not active at 50°C Tetrahymena thermophila

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
7
-
-
Tetrahymena thermophila

pH Stability

pH Stability pH Stability Maximum Comment Organism
4 8.5 the enzyme is not active beyond the pH limits of pH 4.5 and 8.0 Tetrahymena thermophila

IC50 Value

IC50 Value IC50 Value Maximum Comment Organism Inhibitor Structure
0.00003
-
pH 7.0, 30°C Tetrahymena thermophila 2,3-iminosqualene
0.00004
-
pH 7.0, 30°C Tetrahymena thermophila Ro 43-8522
0.00005
-
pH 7.0, 30°C Tetrahymena thermophila N,N-Dimethyldodecylamine-N-oxide