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Literature summary extracted from

  • Schwarz, A.; Brecker, L.; Nidetzky, B.
    Probing the active site of Corynebacterium callunae starch phosphorylase through the characterization of wild-type and His334-->Gly mutant enzymes (2007), FEBS J., 274, 5105-5115.
    View publication on PubMed

Activating Compound

EC Number Activating Compound Comment Organism Structure
2.4.1.1 imidazole stimulates activity of the mutant up to 5.5fold Corynebacterium callunae

Protein Variants

EC Number Protein Variants Comment Organism
2.4.1.1 H334G purified H334G shows 0.05% and 1.3% of wild-type catalytic center activity for phosphorolysis of maltopentaose and substrate binding affinity in the ternary complex with enzyme bound to phosphate, respectively. Disruption of enzyme-substrate interactions in H334G is strictly local, affecting the protein environment of sugar carbon 6. pH profiles of the phosphorolysis rate for wild-type and H334G are both bell-shaped, with the broad pH range of optimum activity in the wild-type (pH 6.5-7.5) being narrowed and markedly shifted to lower pH values in the mutant (pH 6.5-7.0). External imidazole partly restores the activity lost in the mutant, without participating as an alternative nucleophile in the reaction Corynebacterium callunae

Inhibitors

EC Number Inhibitors Comment Organism Structure
2.4.1.1 2-ethylimidazole weak inhibition of wild-type activity, inhibition of mutant enzyme H334G Corynebacterium callunae
2.4.1.1 2-methylimidazole weak inhibition of wild-type activity Corynebacterium callunae
2.4.1.1 acetate weak inhibition of wild-type activity, no effect on the activity of the H334G mutant Corynebacterium callunae
2.4.1.1 azide weak inhibition of wild-type activity Corynebacterium callunae
2.4.1.1 formate 5fold reduction of wild-type activity, no effect on the activity of the H334G mutant Corynebacterium callunae
2.4.1.1 imidazole weak inhibition of wild-type enzyme Corynebacterium callunae

KM Value [mM]

EC Number KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
2.4.1.1 280
-
 maltopentaose pH 7.0 Corynebacterium callunae

Organism

EC Number Organism UniProt Comment Textmining
2.4.1.1 Corynebacterium callunae Q8KQ56
-
-

Purification (Commentary)

EC Number Purification (Comment) Organism
2.4.1.1 Wild-type and the H334G mutant enzyme produced in Escherichia coli Corynebacterium callunae

Substrates and Products (Substrate)

EC Number Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
2.4.1.1 maltopentaose + phosphate
-
 Corynebacterium callunae ?
-
 ?

Synonyms

EC Number Synonyms Comment Organism
2.4.1.1 CcStP
-
 Corynebacterium callunae
2.4.1.1 starch phosphorylase
-
 Corynebacterium callunae

Turnover Number [1/s]

EC Number Turnover Number Minimum [1/s] Turnover Number Maximum [1/s] Substrate Comment Organism Structure
2.4.1.1 0.033
-
 maltopentaose pH 7.0 Corynebacterium callunae

pH Optimum

EC Number pH Optimum Minimum pH Optimum Maximum Comment Organism
2.4.1.1 6.5 7.5 phosphorolysis of maltopdextrin, wild-type enzyme Corynebacterium callunae
2.4.1.1 6.5 7 phosphorolysis of maltopdextrin, mutant enzyme H334G Corynebacterium callunae

Cofactor

EC Number Cofactor Comment Organism Structure
2.4.1.1 pyridoxal 5'-phosphate the 31P chemical shift of pyridoxal 5'-phosphate in the wild-type was pH-dependent and not perturbed by binding of arsenate. At pH 7.25, it is not sensitive to the replacement His334 by Gly Corynebacterium callunae