THE DEGRADATION OF CALF THYMUS DEOXYRIBONUCLEIC ACID BY PANCREATIC DEOXYRIBONUCLEASE

1958 ◽  
Vol 36 (12) ◽  
pp. 1251-1256 ◽  
Author(s):  
R. O. Hurst

The hydrolysis of deoxyribonucleic acid by pancreatic deoxyribonuclease was studied using high concentrations of enzyme. An increased production of material soluble in uranyl acetate reagent was obtained. Evidence for heterogeneity in the activity of the enzyme is presented.

1958 ◽  
Vol 36 (1) ◽  
pp. 1251-1256 ◽  
Author(s):  
R. O. Hurst

The hydrolysis of deoxyribonucleic acid by pancreatic deoxyribonuclease was studied using high concentrations of enzyme. An increased production of material soluble in uranyl acetate reagent was obtained. Evidence for heterogeneity in the activity of the enzyme is presented.


1960 ◽  
Vol 38 (1) ◽  
pp. 347-354 ◽  
Author(s):  
R. O. Hurst ◽  
Dorothy Findlay

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.


Biochemistry ◽  
1968 ◽  
Vol 7 (1) ◽  
pp. 406-411 ◽  
Author(s):  
George W. Rushizky ◽  
Isabelle H. Skavenski ◽  
Antoinette E. Greco

1963 ◽  
Vol 41 (1) ◽  
pp. 469-480 ◽  
Author(s):  
R. O. Hurst ◽  
G. C. Becking

The oligonucleotides obtained from deoxyribonucleic acid by the action of pancreatic deoxyribonuclease in the presence of magnesium ions or manganous ions have been analyzed by ion exchange chromatography and by determination of the relative amounts of purine and pyrimidine deoxynucleotides occupying the 5′-terminal position. Evidence of a difference in the specificity of action of the enzyme that is dependent upon the nature of the metal ion activator employed has been adduced.


1960 ◽  
Vol 38 (4) ◽  
pp. 347-354 ◽  
Author(s):  
R. O. Hurst ◽  
Dorothy Findlay

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.


1963 ◽  
Vol 41 (2) ◽  
pp. 469-480 ◽  
Author(s):  
R. O. Hurst ◽  
G. C. Becking

The oligonucleotides obtained from deoxyribonucleic acid by the action of pancreatic deoxyribonuclease in the presence of magnesium ions or manganous ions have been analyzed by ion exchange chromatography and by determination of the relative amounts of purine and pyrimidine deoxynucleotides occupying the 5′-terminal position. Evidence of a difference in the specificity of action of the enzyme that is dependent upon the nature of the metal ion activator employed has been adduced.


Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4343
Author(s):  
Lena Mitousis ◽  
Hannes Maier ◽  
Luka Martinovic ◽  
Andreas Kulik ◽  
Sigrid Stockert ◽  
...  

Tobramycin is a broad-spectrum aminoglycoside antibiotic agent. The compound is obtained from the base-catalyzed hydrolysis of carbamoyltobramycin (CTB), which is naturally produced by the actinomycete Streptoalloteichus tenebrarius. However, the strain uses the same precursors to synthesize several structurally related aminoglycosides. Consequently, the production yields of tobramycin are low, and the compound’s purification is very challenging, costly, and time-consuming. In this study, the production of the main undesired product, apramycin, in the industrial isolate Streptoalloteichus tenebrarius 2444 was decreased by applying the fermentation media M10 and M11, which contained high concentrations of starch and dextrin. Furthermore, the strain was genetically engineered by the inactivation of the aprK gene (∆aprK), resulting in the abolishment of apramycin biosynthesis. In the next step of strain development, an additional copy of the tobramycin biosynthetic gene cluster (BGC) was introduced into the ∆aprK mutant. Fermentation by the engineered strain (∆aprK_1-17L) in M11 medium resulted in a 3- to 4-fold higher production than fermentation by the precursor strain (∆aprK). The phenotypic stability of the mutant without selection pressure was validated. The use of the engineered S. tenebrarius 2444 facilitates a step-saving, efficient, and, thus, more sustainable production of the valuable compound tobramycin on an industrial scale.


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