scholarly journals Kinetic mechanism from steady-state kinetics of the reaction catalysed by baker's-yeast glucose 6-phosphate dehydrogenase in solution and covalently attached to sepharose

1976 ◽  
Vol 157 (2) ◽  
pp. 389-393 ◽  
Author(s):  
B J Gould ◽  
M A Goheer
Keyword(s):  
Immobilized Enzyme ◽  
Packed Bed ◽  
Kinetic Mechanism ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Soluble Enzyme ◽  
Steady State Kinetics ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Sepharose 4B ◽  
Kinetics Of

1. The reaction catalysed by glucose 6-phosphate dehydrogenase (D-glucose 6-phosphate-NADP+ oxidoreductase, EC 1.1.1.49) from baker's yeast was studied in 42mM-glycylglycine buffer, pH7.4 at 25 degrees C, by initial-velocity studies and by the use of NADPH as a product inhibitor. 2. The reactions catalysed by both the soluble enzyme and a stable enzyme covalently attached to CNBr-activated Sepharose 4B probably follow an ordered reaction mechanism with NADP+ and NADPH as the leading reactants. 3. The kinetic constants obtained for the soluble enzyme lere: KNADP+m, 19 muM; KNADP+s, 23 muM; KNADPHs, 15 muM. Similar values were obtained for the immobilized enzyme. 4. The assay of the immobilized enzyme was done by using a micro packed-bed recirculation reactor, and the advantages of this technique are discussed.

scholarly journals Preparation of immobilized baker's-yeast glucose 6-phosphate dehydrogenase attached to modified sepharose and sephadex and a comparison of the properties of these preparations with those of the soluble enzyme

1976 ◽  
Vol 157 (2) ◽  
pp. 289-294 ◽  
Author(s):  
M A Goheer ◽  
B J Gould ◽  
D V Parke
Keyword(s):  
Immobilized Enzyme ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Soluble Enzyme ◽  
Ph Optimum ◽  
Yeast Saccharomyces Cerevisiae ◽  
Enzyme Preparations ◽  
Ph Range ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Sepharose 4B

1. Glucose 6-phosphate dehydrogenase (D-glucose 6-phosphate-NADP+ oxidoreductase, EC 1.1.1.49) from baker's yeast (Saccharomyces cerevisiae) was immobilized on CNBr-activated Sepharose 4B with retention of about 3% of enzyme activity. This uncharged preparation was stable for up to 4 months when stored in borate buffer, pH7.6, at 4 degrees C. 2. Stable enzyme preparations with negative or positive overall charge were made by adding valine or ethylenediamine to the CNBr-activated Sepharose 4B 30min after addition of the enzyme. 3. These three immobilized enzyme preparations retained 40-60% of their activity after 15 min at 50 degrees C. The soluble enzyme is inactivated by these conditions. 4. The soluble enzyme lost 45 and 100% of its activity on incubation for 3h at pH6 and 10 respectively. The three immobilized-enzyme preparations were completely stable over this entire pH range. 5. The pH optimum of the positively and negatively charged immobilized-enzyme preparations were about 8 and 9 respectively. The soluble enzyme and the uncharged immobilized enzyme had an optimum pH at about 8.5 6. Glucose 6-phosphate dehydrogenase immobilized on CNBr-activated Sephadex G-25 was unstable, as was enzyme attached to CNBr-activated Sepharose 4B to which glycine, asparitic acid, valine or ethylenediamine was added at the same time as the enzyme.

scholarly journals Evaluation of the Fermentation Dynamics of Commercial Baker’s Yeast in Presence of Pistachio Powder to Produce Lysine-Enriched Breads

Fermentation ◽  
2019 ◽  
Vol 6 (1) ◽  
pp. 2 ◽  
Author(s):  
Antonio Alfonzo ◽  
Raimondo Gaglio ◽  
Marcella Barbera ◽  
Nicola Francesca ◽  
Giancarlo Moschetti ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Density ◽  
Titratable Acidity ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Yeast Saccharomyces Cerevisiae ◽  
Promising Strategy ◽  
Total Titratable Acidity ◽  
Bread Production ◽  
Kinetics Of

The present work was carried out to evaluate the microbiological, physicochemical, and sensory characteristics of fortified pistachio breads. Pistachio powder (5% w/w) was added to flour or semolina and fermented by a commercial baker’s yeast (Saccharomyces cerevisiae). Pistachio powder did not influence the biological leavening of the doughs. The kinetics of pH and total titratable acidity (TTA) during dough fermentation showed that the leavening process occurred similarly for all trials. The concentration of yeasts increased during fermentation and reached levels of 108 CFU/g after 2 h. Pistachio powder decreased the height and softness of the final breads and increased cell density of the central slices. The amount of lysine after baking increased in pistachio breads and this effect was stronger for semolina rather than flour trials. Sensory evaluation indicated that fortified breads processed from semolina were those more appreciated by the judges. This work clearly indicated that the addition of pistachio powder in bread production represents a promising strategy to increase the availability of lysine in cereal-based fermented products.

Kinetics of protein secretion and fractionation in Baker's yeast fermentations

2007 ◽  
Vol 39 (2) ◽  
pp. 85-91 ◽  
Author(s):  
Don-Hee Park ◽  
George W. Malaney ◽  
Robert D. Tanner
Keyword(s):  
Protein Secretion ◽  
Baker’S Yeast ◽  
Baker's Yeast ◽  
Kinetics Of

scholarly journals The kinetic mechanism of the major form of ox kidney aldehyde reductase with d-glucuronic acid

1982 ◽  
Vol 205 (2) ◽  
pp. 381-388 ◽  
Author(s):  
Ann K. Daly ◽  
Timothy J. Mantle
Keyword(s):  
Glucuronic Acid ◽  
Alternative Pathway ◽  
Kinetic Mechanism ◽  
Product Inhibition ◽  
Aldehyde Reductase ◽  
Major Form ◽  
Mechanism Of Inhibition ◽  
Steady State Kinetics ◽  
Inhibition Studies ◽  
Kinetics Of

The steady-state kinetics of the major form of ox kidney aldehyde reductase with d-glucuronic acid have been determined at pH7. Initial rate and product inhibition studies performed in both directions are consistent with a Di-Iso Ordered Bi Bi mechanism. The mechanism of inhibition by sodium valproate and benzoic acid is shown to involve flux through an alternative pathway.

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