Purification and properties of a heat-stable and cold-labile NAD-specific glutamate dehydrogenase from Sporosarcina ureae

1994 ◽  
Vol 161 (6) ◽  
pp. 531-534 ◽  
Author(s):  
Thomas Jahns ◽  
Heinrich Kaltwasser
Keyword(s):  
Glutamate Dehydrogenase ◽  
Sporosarcina Ureae ◽  
Heat Stable ◽  
Purification And Properties

scholarly journals An NADP-Glutamate Dehydrogenase from the Green Alga Bryopsis maxima. Purification and Properties

1997 ◽  
Vol 38 (3) ◽  
pp. 327-335 ◽  
Author(s):  
R. Inokuchi ◽  
T. Itagaki ◽  
J. T. Wiskich ◽  
K. Nakayama ◽  
M. Okada
Keyword(s):  
Glutamate Dehydrogenase ◽  
Green Alga ◽  
Purification And Properties ◽  
Bryopsis Maxima

Purification and properties of polygalacturonic acid trans-eliminase from Bacillus stearothermophilus

1980 ◽  
Vol 26 (3) ◽  
pp. 377-384 ◽  
Author(s):  
A. Karbassi ◽  
R. H. Vaughn
Keyword(s):  
Bacillus Stearothermophilus ◽  
Ethylenediaminetetraacetic Acid ◽  
Thermophilic Bacteria ◽  
Maximum Activity ◽  
Polygalacturonic Acid ◽  
Pectic Acid ◽  
Heat Stable ◽  
Pectolytic Activity ◽  
Purification And Properties ◽  
Optimal Ph

A strain of thermophilic bacteria, Bacillus stearothermophilus, with pectolytic activity has been isolated. It produced an endo-polygalacturonic acid trans-eliminase (endo-PATE, EC 4.2.2.1) extracellularly when grown at 65 °C on a pectic acid medium. The PATE was purified 62-fold by the rapid affinity chromatographic method on a Sepharose–polygalacturonamide linked matrix. The absorbed PATE was eluted from the column with a continuous gradient of 0–10−3 M ethylenediaminetetraacetic acid (EDTA) in phosphate buffer at pH 7.6.The endo-PATE of this organism was much more heat stable than similar enzymes from the mesophilic Bacillus polymyxa and the thermotolerant Bacillus pumilus. The maximum activity of the enzyme occurred at 70 °C. With pectic acid as the substrate, the endo-PATE had an optimal pH of 9.0, the highest optimal pH compared with those of similar enzymes from other species of the genus.The molecular weight of the endo-PATE, as determined by chromatography on a Sephadex G-100 gel column, was 24 000.

scholarly journals Purification and properties of Penicillium glucose 6-phosphate dehydrogenase

1972 ◽  
Vol 128 (4) ◽  
pp. 817-831 ◽  
Author(s):  
A. Anne Malcolm ◽  
M. G. Shepherd
Keyword(s):  
Molecular Weight ◽  
Thermal Inactivation ◽  
Gradient Centrifugation ◽  
Sucrose Density Gradient ◽  
Thermophilic Fungus ◽  
Sucrose Density Gradient Centrifugation ◽  
Coenzyme Specificity ◽  
Heat Stable ◽  
Purification And Properties ◽  
Glucose 6 Phosphate Dehydrogenase

1. Glucose 6-phosphate dehydrogenase was isolated and partially purified from a thermophilic fungus, Penicillium duponti, and a mesophilic fungus, Penicillium notatum. 2. The molecular weight of the P. duponti enzyme was found to be 120000±10000 by gelfiltration and sucrose-density-gradient-centrifugation techniques. No NADP+- or glucose 6-phosphate-induced change in molecular weight could be demonstrated. 3. Glucose 6-phosphate dehydrogenase from the thermophilic fungus was more heat-stable than that from the mesophile. Glucose 6-phosphate, but not NADP+, protected the enzyme from both the thermophile and the mesophile from thermal inactivation. 4. The Km values determined for glucose 6-phosphate dehydrogenase from the thermophile P. duponti were 4.3×10−5m-NADP+ and 1.6×10−4m-glucose 6-phosphate; for the enzyme from the mesophile P. notatum the values were 6.2×10−5m-NADP+ and 2.5×10−4m-glucose 6-phosphate. 5. Inhibition by NADPH was competitive with respect to both NADP+ and glucose 6-phosphate for both the P. duponti and P. notatum enzymes. The inhibition pattern indicated a rapid-equilibrium random mechanism, which may or may not involve a dead-end enzyme–NADP+–6-phosphogluconolactone complex; however, a compulsory-order mechanism that is consistent with all the results is proposed. 6. The activation energies for the P. duponti and P. notatum glucose 6-phosphate dehydrogenases were 40.2 and 41.4kJ·mol−1 (9.6 and 9.9kcal·mol−1) respectively. 7. Palmitoyl-CoA inhibited P. duponti glucose 6-phosphate dehydrogenase and gave an inhibition constant of 5×10−6m. 8. Penicillium glucose 6-phosphate dehydrogenase had a high degree of substrate and coenzyme specificity.

Glutamate Dehydrogenase from Pea Roots: Purification and Properties of the Enzyme

1971 ◽  
Vol 49 (1) ◽  
pp. 127-138 ◽  
Author(s):  
E. Pahlich ◽  
K. W. Joy
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Glutamate Dehydrogenase ◽  
Constant Ratio ◽  
Ph Optimum ◽  
Purification And Properties ◽  
Activity Ratios ◽  
Single Protein ◽  
Michaelis Constants ◽  
Pea Roots

Glutamate dehydrogenase (L-glutamate: NAD+ oxidoreductase (deaminating), EC 1.4.1.2) has been purified 1250-fold from pea roots. The preparation contains only a single protein, and the molecular weight was estimated to be 208 000 ± 10 000. The enzyme shows NADH (aminating) and NAD+ (deaminating) activities, but the ratio of these activities is not constant and can be changed experimentally. NADPH activity is also present and shows a relatively constant ratio to NAD+ activity. EDTA inhibits NADH activity in intermediate concentrations, but reactivates at higher concentrations. NAD+ (and NADPH) activity is only slightly changed by EDTA. The effects of dioxane and the coenzymes on the enzyme are also reported. Mechanisms which could explain the different activity ratios, in terms of two interconvertible enzyme forms, are discussed.The pH optimum for NADH and NAD+ activities is about pH 8.0. Michaelis constants were found to be: α-ketoglutarate, 3.3 × 10−3 M; ammonium (sulfate), 3.8 × 10−2 M; glutamate, 7.3 × 10−3 M; NADH, 8.6 × 10−4 M; NAD+, 6.5 × 10−4 M. The enzyme is highly specific for the substrates glutamate and α-ketoglutarate, showing no alanine or aspartate dehydrogenase activity, and no deamination with a range of amino acids.

THE PURIFICATION AND PROPERTIES OF RAT BRAIN GLUTAMATE DEHYDROGENASE

1979 ◽  
Vol 33 (1) ◽  
pp. 53-60 ◽  
Author(s):  
Po Yok Chee ◽  
June L. Dahl ◽  
Leonard A. Fahien
Keyword(s):  
Rat Brain ◽  
Glutamate Dehydrogenase ◽  
Purification And Properties
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