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Literature summary for 2.4.1.19 extracted from

  • Lee, K.W.; Shin, H.D.; Lee, Y.H.
    Catalytic function and affinity purification of site-directed mutant beta-cyclodextrin glucanotransferase from alkalophilic Bacillus firmus var. alkalophilus (2003), J. Mol. Catal. B, 26, 157-165.
No PubMed abstract available
Search for more literature for 2.4.1.19

Cloned(Commentary)

Cloned (Comment) Organism
mutant enzymes H59Q, Y96M, 90-PPI-92, and DELTA(154–160) are constructed and produced using a recombinant Escherichia coli with a secretive expression system extracellularly Cytobacillus firmus

Protein Variants

Protein Variants Comment Organism
DELTA154–160 mutation increases cyclization activity around 1.5times without any significant reduction of coupling and hydrolyzing activities, conversion yield into cyclodextrins is 39% higher than that of wild-type enzyme without any recognizable change in cyclodextrin ratio. pH-Stability decreases drastically in acidic pH region. Decrease in thermal stability Cytobacillus firmus
Y96M mutation increases cyclization activity around 1.5times without any significant reduction of coupling and hydrolyzing activities, conversion yield into cyclodextrins is 28.6% higher than that of wild-type enzyme without any recognizable change in cyclodextrin ratio. Decrease in thermal stability Cytobacillus firmus

Organism

Organism UniProt Comment Textmining
Cytobacillus firmus
-
 var. alkalophilus
-

Purification (Commentary)

Purification (Comment) Organism
wild-type enzyme and mutant enzymes H59Q, Y96M, 90-PPI-92, and DELTA(154–160) expressed in Escherichia coli Cytobacillus firmus

Specific Activity [micromol/min/mg]

Specific Activity Minimum [µmol/min/mg] Specific Activity Maximum [µmol/min/mg] Comment Organism
142
-
 mutant enzyme H59Q, cyclization activity Cytobacillus firmus
226
-
 wild-type enzym, cyclization activity Cytobacillus firmus
332
-
 mutant enzyme Y96M, cyclization activity Cytobacillus firmus
342
-
 mutant enzyme DELTA154-160, cyclization activity Cytobacillus firmus

Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
starch + maltose
-
 Cytobacillus firmus beta-cyclodextrin + gamma-cyclodextrin + maltooligosaccharides
-
 ?

Temperature Stability [°C]

Temperature Stability Minimum [°C] Temperature Stability Maximum [°C] Comment Organism
60
-
 stable up to wild-type enzyme Cytobacillus firmus
70
-
 30 min, about 50% loss of activity of wild-type enzyme, about 70% loss of activity of mutant enzymes DELTA154-160 and Y96M Cytobacillus firmus

pH Optimum

pH Optimum Minimum pH Optimum Maximum Comment Organism
6.5
-
 wild-type enzyme Cytobacillus firmus

pH Range

pH Minimum pH Maximum Comment Organism
4 8.5 pH 4.0: about 65% of maximal activity, pH 8.5: about 65% of maximal activity, wild-type enzyme Cytobacillus firmus