THE HETEROGENEITY OF PANCREATIC DEOXYRIBONUCLEASE

1962 ◽  
Vol 40 (2) ◽  
pp. 165-175 ◽  
Author(s):  
G. C. Becking ◽  
R. O. Hurst
Keyword(s):  
Enzyme Activity ◽  
Ionic Strength ◽  
Enzyme Preparation ◽  
Deoxyribonucleic Acid ◽  
Paper Electrophoresis ◽  
Relative Activity ◽  
Enzyme Concentration ◽  
Uranyl Acetate ◽  
Ph Optimum

The action of crystalline pancreatic deoxyribonuclease on sodium oligonucleotides in the presence of manganous ions has been studied and a pH optimum of 6.6 observed. Inhibition of the enzyme activity by increased ionic strength of the digest occurred. The liberation of products soluble in uranyl acetate – trichloroacetate was found to vary with enzyme concentration and the relative activity of the enzyme on oligonucleotides was best determined by a logarithm-plot method. The activity of the enzyme towards deoxyribonucleic acid or sodium oligonucleotides as substrate was not affected by treatment with acetone. Evidence of heterogeneity in the crystalline enzyme preparation was obtained using paper electrophoresis and chromatography on carboxymethylcellulose. Two fractions were separated that showed different ratios of activity towards the two substrates employed.

THE HETEROGENEITY OF PANCREATIC DEOXYRIBONUCLEASE

1962 ◽  
Vol 40 (1) ◽  
pp. 165-175 ◽  
Author(s):  
G. C. Becking ◽  
R. O. Hurst
Keyword(s):  
Enzyme Activity ◽  
Ionic Strength ◽  
Enzyme Preparation ◽  
Deoxyribonucleic Acid ◽  
Paper Electrophoresis ◽  
Relative Activity ◽  
Enzyme Concentration ◽  
Uranyl Acetate ◽  
Ph Optimum

The action of crystalline pancreatic deoxyribonuclease on sodium oligonucleotides in the presence of manganous ions has been studied and a pH optimum of 6.6 observed. Inhibition of the enzyme activity by increased ionic strength of the digest occurred. The liberation of products soluble in uranyl acetate – trichloroacetate was found to vary with enzyme concentration and the relative activity of the enzyme on oligonucleotides was best determined by a logarithm-plot method. The activity of the enzyme towards deoxyribonucleic acid or sodium oligonucleotides as substrate was not affected by treatment with acetone. Evidence of heterogeneity in the crystalline enzyme preparation was obtained using paper electrophoresis and chromatography on carboxymethylcellulose. Two fractions were separated that showed different ratios of activity towards the two substrates employed.

THE ACTION OF PANCREATIC DEOXYRIBONUCLEASE ON OLIGONUCLEOTIDES FROM CALF THYMUS DEOXYRIBONUCLEIC ACID

1960 ◽  
Vol 38 (1) ◽  
pp. 347-354 ◽  
Author(s):  
R. O. Hurst ◽  
Dorothy Findlay
Keyword(s):  
Enzyme Activity ◽  
Metal Ions ◽  
Enzyme Preparation ◽  
Deoxyribonucleic Acid ◽  
Chelating Agent ◽  
Assay Method ◽  
Calf Thymus ◽  
Additional Support ◽  
Hydrolysis Of

Hydrolysis of sodium oligonucleotide by crystalline pancreatic deoxyribonuclease (DNA-ase) has been studied in the presence of different metal ions and the chelating agent ethylenediaminetetraacetate (EDTA). Although EDTA inhibited the action of DNA-ase when magnesium or cobaltous ions were used as activator, the enzyme activity was enhanced in the presence of manganous ions and EDTA. The results are interpreted as indicating the presence of an oligonucleotidase function in the enzyme preparation. A differential assay method for DNA-ase and oligonucleotidase activity has been devised and the evidence obtained gives additional support for this conclusion.

Studies on Partially Purified Pig Liver Steroid Δ4-5β-Reductase Activity

1973 ◽  
Vol 51 (12) ◽  
pp. 1661-1668 ◽  
Author(s):  
Edward J. Van Doorn ◽  
John C. Nduaguba ◽  
Albert F. Clark
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Enzyme Preparation ◽  
Reductase Activity ◽  
Enzymatic Reaction ◽  
Ph Optimum ◽  
Pig Liver ◽  
Liver Cytosol ◽  
End Products ◽  
Tris Maleate

Some properties of partially purified steroid Δ4-5β-reductase activity of pig liver cytosol have been studied using testosterone as substrate. The enzymatic activity was stable for 72 h at 4° when stored in 0.05 M Tris–maleate buffer, pH 7.4 or 8.4; storage at pH 8 at 4° resulted in a 25% decrease in activity in 30 days. The pH optimum in Tris–maleate buffers was 6.4. Enzyme activity was completely inhibited by 0.2 mM p-chloromercuribenzenesulfonate and 0.2 mM p-chloromercuribenzoate. Enzyme activity was reduced by 20% and 45% with 1.0 mM iodoacetamide and 1.0 mM N-ethylmaleimide, respectively. The end products of the enzymatic reaction, NADP+ and 5β-dihydrotestosterone, inhibited the rate of reduction of testosterone. Testosterone Δ4-5β-reductase activity was present in protein of molecular weight 25 000–30 000, as determined by gel filtration.The enzyme preparation reduced a variety of C19 and C21 steroids. The highest activity (twice that for testosterone) was found with aldosterone as substrate.

Purification and properties of endo-β-glucanase in the yeast Hanseniaspora valbyensis

1969 ◽  
Vol 15 (7) ◽  
pp. 697-701 ◽  
Author(s):  
Ahmed T. H. Abd-El-Al ◽  
H. J. Phaff
Keyword(s):  
Enzyme Activity ◽  
Cell Walls ◽  
Carbon Sources ◽  
Culture Fluid ◽  
Extracellular Enzyme ◽  
Enzyme Concentration ◽  
Random Pattern ◽  
Ph Optimum ◽  
Hanseniaspora Uvarum ◽  
Purification And Properties

Endo-β-glucanase was detected in Hanseniaspora valbyensis and Hanseniaspora uvarum. The extracellular enzyme activity of H. valbyensis was maximal with vigorous aeration at 30 C in a complete mineral medium with glucose and 0.2 M Na-succinate buffer. The enzyme concentration was lower when the buffer was 0.05 M Na-succinate. The use of a variety of carbon sources, including yeast cell walls, failed to induce higher enzyme activities. The enzyme was purified 34-fold from the culture fluid of H. valbyensis. The purified enzyme had a broad pH optimum between pH 3.5 and 4.5. Among the known β-glucan homopolymers, only laminarin (β-1 → 3 bonds) was hydrolyzed by the enzyme. The Km for laminarin was 0.11 mg/ml and the Vmax was 0.835 μmoles glucose equivalents/min mg protein. No action was detected with laminaribiose, laminaritriose, or oat glucan. Laminaritetraose, however, was hydrolyzed slowly in a random pattern. These results suggest the requirement for three consecutive β-1 → 3 bonds for activity.

scholarly journals Reactional Ultrasonic Systems And Microwave Irradiation For Pretreatment Of Agro-Industrial Waste To Increase Enzymatic Activity

2020 ◽  
Author(s):  
Fabiane Fernanda Czapela ◽  
Simone Kubeneck ◽  
Karina Paula Preczeski ◽  
Caroline Dalastra ◽  
Thamarys Scapini ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Reaction System ◽  
Relative Activity ◽  
Enzyme Concentration ◽  
Enzymatic Extract ◽  
Ultrasonic Probe ◽  
Enzymatic Production ◽  
Concentration Technique ◽  
Commercial Enzymes ◽  
Waste Degradation

Abstract Pretreatment of keratinous residues using an ultrasonic reaction system provides greater enzymatic production in less time. This is a promising technology for measuring enzyme activity and microwave processes. In the present work, an ultrasonic probe reaction system was used to evaluate the potential of swine hair pretreatment. The pretreated material was submerged with non-pretreated residues for 9 days to obtain the enzyme. Enzyme activity was measured in the extracts obtained using the ultrasonic probe, ultrasonic bath, and microwave. We also used the enzymatic concentration technique with NaCl and acetone. Homemade enzymatic extracts were evaluated for their ability to degrade swine hair and chicken feathers by comparing them with the activities commercial enzymes. Macrobeads gave greater energy dissipation in less time, providing greater enzyme activity (50.8 U/mL over 3 days). In terms of waste degradation, non-pretreated swine hair was more promising. The ultrasonic probe reaction system had the potential to evaluate increased enzyme activity (38.4% relative activity) and the enzyme concentration increased activity by 53.5%. The homemade enzymatic extract showed promise for degradation of keratinous residues.

UDP-Glucose: Anthocyanidin/FIavonol 3-O-Glucosyltransferase in Enzyme Preparation from Flower Extracts of Genetically Defined Lines of Matthiola incana R. Br.

1986 ◽  
Vol 41 (7-8) ◽  
pp. 699-706 ◽  
Author(s):  
M. Teusch ◽  
G. Forkmann ◽  
W. Seyffert
Keyword(s):  
Enzyme Activity ◽  
Structural Gene ◽  
Enzyme Preparation ◽  
Reaction Rate ◽  
Flower Colour ◽  
Hydroxyl Group ◽  
Anthocyanin Synthesis ◽  
Ph Optimum ◽  
Matthiola Incana ◽  
Highly Active

Abstract In flower extracts of Matthiola incana an enzyme catalyzing the transfer of glucose from UDP- glucose to the hydroxyl group at 3-position of anthocyanidins and flavonols was demonstrated. The pH-optimum of this reaction is at pH 8.5 for pelargonidin and pH 9.5 for quercetin as substrate. The reaction is inhibited by both substrates above 10 nmol per assay. The enzyme is highly active, within 30 sec 3 nmol of 3-glucosides were formed. At 30 °C the enzyme is stable for hours and at -20 °C months. Besides UDP-glucose, TDP-glucose is a suitable glucosyl-donor, but with a reduced (70%) reaction rate. Enzyme activity is clearly inhibited by Fe2+ and Cu2+ ions, and by diethylpyrocarbonate. Acyanic or pale coloured mutants of several genes interfering with anthocyanin synthesis after dihydroflavonol formation show a more or less drastically reduced enzyme activity (5-40%). But none of these genes can be regarded as the structural gene for the 3-glucosyltransferase. The influence of these genes on enzyme activity and flower colour is dis­cussed.

scholarly journals LIPASE IMMOBILIZATION ON FIBERS GRAFTED WITH POLYGLYCIDYL METHACHRYLATE

2019 ◽  
Vol 20 (1) ◽  
pp. 12-23
Author(s):  
Maan Alkhatib ◽  
Nik Adlin Bahrudin ◽  
HAMZAH M. SALLEH ◽  
Mohamed M. E. Nasef ◽  
Teo M. Ting
Keyword(s):  
Enzyme Activity ◽  
Storage Stability ◽  
Immobilized Enzyme ◽  
Immobilized Lipase ◽  
Enzyme Concentration ◽  
Free Enzyme ◽  
Effect Of Temperature ◽  
Ph Optimum ◽  
Lipase Enzyme ◽  
Central Composite

ABSTRACT: Lipase enzyme originated from wheat germ was immobilized on nylon -6- grafted with polyglycidyl methachrylate (PGMA). The immobilization of enzyme experiments were designed and studied using face centred central composite design (FCCCD) under response surface methodology (RSM). Prior to immobilization, the polymer was activated with diethyl amine/ethanol to introduce an amine functional group to facilitate covalent bonding with the enzyme. The immobilized and free enzymes were characterized for effect of temperature and pH on enzyme activity, stability, storage and reusability as well as kinetics studies. ANOVA revealed that optimum lipase activity of 0.287 U/ml was achieved at immobilization time of 5 h, pH of 6 and 1.0 mg/ml for enzyme concentration. The optimum temperatures and pH for immobilized and free enzymes were 45 °C and 35 °C, and 8 and 7, respectively. The immobilized enzyme showed higher stability compared to free enzyme. The immobilized enzyme retained 18% of its activity after being recycled 8 times. In a storage stability test, immobilized lipase was able to retain 70% of its activity after being stored for 30 days, while free enzyme activity dropped to 15 % after 20 days of storage. ABSTRAK:Enzim Lipase telah dihasilkan daripada mikroorganisma pegun gandum di atas nilon -6- dan digraf bersama poliglisidel methakrilet (PGMA). Enzim pegun ini direka dan dikaji secara eksperimen menggunakan reka bentuk campuran pusat pada permukaan (FCCCD) di bawah kaedah tindak balas permukaan (RSM). Sebelum menjadi pegun, polimer ini telah diaktifkan dengan dietil amine/ethanol bagi menghasilkan kumpulan fungsi amine bagi membantu ikatan kovalen atom pada enzim. Enzim pegun dan bebas ini telah dikategorikan mengikut kesan enzim ke atas suhu, aktiviti enzim ke atas kesan pH, kestabilan, keboleh-simpanan dan keboleh-gunaan balik, serta ujian tindak balas kinetik. ANOVA membuktikan bahawa aktiviti optimum enzim lipase ini adalah sebanyak 0.287 U/ml telah terhasil selama 5 jam pegun, pada pH 6 dan kepekatan enzim sebanyak 1.0 mg/ml. Suhu dan pH optimum, pada enzim pegun dan enzim bebas ini adalah pada 45 °C dan 35 °C, dan pH 8 dan 7, masing-masing. Enzim pegun ini menunjukkan lebih stabil daripada enzim bebas. Enzim pegun dilihat kekal 18% daripada aktivitinya selepas 8 kali ulangan. Melalui ujian kestabilan simpanan, enzim lipase pegun dapat mengekalkan 70% daripada aktivinya selepas disimpan selama 30 hari, manakala aktiviti enzim bebas telah menurun kepada 15% selepas 20 hari dalam simpanan.

scholarly journals Reactional Ultrasonic Systems And Microwave Irradiation For Pretreatment Of Agro-Industrial Waste To Increase Enzymatic Activity

2020 ◽  
Author(s):  
Fabiane Fernanda Czapela ◽  
Simone Kubeneck ◽  
Karina Paula Preczeski ◽  
Caroline Dalastra ◽  
Thamarys Scapini ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Reaction System ◽  
Relative Activity ◽  
Enzyme Concentration ◽  
Enzymatic Extract ◽  
Ultrasonic Probe ◽  
Enzymatic Production ◽  
Concentration Technique ◽  
Commercial Enzymes ◽  
Waste Degradation

Abstract Pretreatment of keratinous residues using an ultrasonic reaction system provides greater enzymatic production in less time. This is a promising technology for measuring enzyme activity and microwave processes. In the present work, an ultrasonic probe reaction system was used to evaluate the potential of swine hair pretreatment. The pretreated material was submerged with non-pretreated residues for 9 days to obtain the enzyme. Enzyme activity was measured in the extracts obtained using the ultrasonic probe, ultrasonic bath, and microwave. We also used the enzymatic concentration technique with NaCl and acetone. Homemade enzymatic extracts were evaluated for their ability to degrade swine hair and chicken feathers by comparing them with the activities commercial enzymes. Macrobeads gave greater energy dissipation in less time, providing greater enzyme activity (50.8 U/mL over 3 days). In terms of waste degradation, non-pretreated swine hair was more promising. The ultrasonic probe reaction system had the potential to evaluate increased enzyme activity (38.4% relative activity) and the enzyme concentration increased activity by 53.5%. The homemade enzymatic extract showed promise for degradation of keratinous residues.

THE ACTION OF PANCREATIC DEOXYRIBONUCLEASE ON OLIGONUCLEOTIDES FROM CALF THYMUS DEOXYRIBONUCLEIC ACID

1960 ◽  
Vol 38 (4) ◽  
pp. 347-354 ◽  
Author(s):  
R. O. Hurst ◽  
Dorothy Findlay
Keyword(s):  
Enzyme Activity ◽  
Metal Ions ◽  
Enzyme Preparation ◽  
Deoxyribonucleic Acid ◽  
Chelating Agent ◽  
Assay Method ◽  
Calf Thymus ◽  
Additional Support ◽  
Hydrolysis Of

Hydrolysis of sodium oligonucleotide by crystalline pancreatic deoxyribonuclease (DNA-ase) has been studied in the presence of different metal ions and the chelating agent ethylenediaminetetraacetate (EDTA). Although EDTA inhibited the action of DNA-ase when magnesium or cobaltous ions were used as activator, the enzyme activity was enhanced in the presence of manganous ions and EDTA. The results are interpreted as indicating the presence of an oligonucleotidase function in the enzyme preparation. A differential assay method for DNA-ase and oligonucleotidase activity has been devised and the evidence obtained gives additional support for this conclusion.

scholarly journals Reactional Ultrasonic Systems and Microwave Irradiation For Pretreatment Of Agro-Industrial Waste To Increase Enzymatic Activity

2020 ◽  
Author(s):  
Fabiane Fernanda Czapela ◽  
Simone Kubeneck ◽  
Karina Paula Preczeski ◽  
Caroline Dalastra ◽  
Thamarys Scapini ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Reaction System ◽  
Relative Activity ◽  
Enzyme Concentration ◽  
Enzymatic Extract ◽  
Ultrasonic Probe ◽  
Enzymatic Production ◽  
Concentration Technique ◽  
Commercial Enzymes ◽  
Waste Degradation

Abstract Pretreatment of keratinous residues using an ultrasonic reaction system provides greater enzymatic production in less time. This is a promising technology for measuring enzyme activity and microwave processes. In the present work, an ultrasonic probe reaction system was used to evaluate the potential of swine hair pretreatment. The pretreated material was submerged with non-pretreated residues for 9 days to obtain the enzyme. Enzyme activity was measured in the extracts obtained using the ultrasonic probe, ultrasonic bath, and microwave. We also used the enzymatic concentration technique with NaCl and acetone. Homemade enzymatic extracts were evaluated for their ability to degrade swine hair and chicken feathers by comparing them with the activities commercial enzymes. Macrobeads gave greater energy dissipation in less time, providing greater enzyme activity (50.8 U/mL over 3 days). In terms of waste degradation, non-pretreated swine hair was more promising. The ultrasonic probe reaction system had the potential to evaluate increased enzyme activity (38.4% relative activity) and the enzyme concentration increased activity by 53.5%. The homemade enzymatic extract showed promise for degradation of keratinous residues.

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