THERMAL ANALYSIS OF POLYANION METACHROMASY: EFFECT OF TEMPERATURE ON METACHROMATIC SOLUTIONS OF NUCLEIC ACIDS AND ACID MUCOPOLYSACCHARIDES

1969 ◽  
Vol 17 (10) ◽  
pp. 651-657 ◽  
Author(s):  
JOHN W. KELLY ◽  
LOUIS CHANG ◽  
FRED ROTHSTEIN
Keyword(s):  
Nucleic Acids ◽  
Toluidine Blue ◽  
Ribonucleic Acid ◽  
Equilibrium Constants ◽  
Linear Functions ◽  
Effect Of Temperature ◽  
A Value ◽  
Acid Mucopolysaccharides ◽  
Common Equation ◽  
Phosphate Groups

Spectra of toluidine blue with acid mucopolysaccharides and nucleic acids were recorded over the temperature range 10-70°C. Metachromatic ratios were inverse, linear functions of temperature. Intercepts and slopes of the thermal plots distinguished acid mucopolysaccharides from nucleic acids. Acid mucopolysaccharide reactions were thermally reversible. Nucleic acid reactions were not strictly reversible; such behavior was not attributable to thermal denaturation. An explanation for the unusual γ-peak of ribonucleic acid-toluidine blue metachromasy is offered in terms of terminal phosphate groups of ribonucleic acid. Solution data in which the polyanion-dye ratio was approximately 1, representing typical "metachromasy," were subjected to thermodynamic analysis. These data did not fit a common equation deriving equilibrium constants spectrophotometrically by variation of reactant concentrations. This failure supported the view of metachromasy as a phenomenon primarily involving dye-dye interaction. Another equation based only on temperature variation yielded a value of –4 kcal/mole for the chondroitin sulfate-toluidine blue complex, in good agreement with similar published values obtained both in solutions and stained materials.

A GRAVIMETRIC STUDY OF HYDRATION OF POLYNUCLEOTIDES

1966 ◽  
Vol 44 (10) ◽  
pp. 1107-1111 ◽  
Author(s):  
Michael Falk
Keyword(s):  
Relative Humidity ◽  
Ribonucleic Acid ◽  
Deoxyribonucleic Acid ◽  
Smooth Functions ◽  
A Value ◽  
General Similarity ◽  
Phosphate Groups

The hydration of soluble ribonucleic acid, of two forms of polyriboadenylic acid, and of nucleohistone was determined gravimetrically as a function of relative humidity (r.h.). The curves are smooth functions of r.h., similar to those obtained earlier for deoxyribonucleic acid. The general similarity of the hydration curves of the polynucleotides so far investigated is in agreement with the suggestion that the ionic phosphate groups are the primary hydration sites in polynucleotides. The hydration data fit the Brunauer–Emmett–Teller equation up to about 75% r.h. and the Harkins–Jura equation at higher values. Both equations yield a value of about 2.0 molecules of H2O per nucleotide for the "monolayer content" for all the polynucleotides investigated.

scholarly journals Säurehydrolyse von Ribonucleinsäure und Desoxyribonucleinsäure

1961 ◽  
Vol 16 (10) ◽  
pp. 673-678 ◽  
Author(s):  
W. Pollmann ◽  
G. Schramm
Keyword(s):  
Enzymatic Hydrolysis ◽  
Nucleic Acids ◽  
Potentiometric Titration ◽  
Ribonucleic Acid ◽  
Deoxyribonucleic Acid ◽  
Potentiometric Method ◽  
Ribonucleic Acids ◽  
Rate Of Hydrolysis ◽  
Phosphate Groups

A method for the potentiometric titration of secondary phosphate groups in nucleic acids is described. Ribonucleic acids of yeast and of microsomes contain 5—6% secondary phosphate groups which cannot be removed by dialysis. The potentiometric method was applied to study several enzymatic hydrolyses and the non-enzymatic hydrolysis between pH 2.4 —1.8. The rate of hydrolysis for the purines and for the phosphate groups is approximately proportional to the H®-concentration. The constants of hydrolysis for ribonucleic acid and for deoxyribonucleic acid were determined. In DNA the depurinisation is 650 times faster than in RNA.

scholarly journals Phosphorus Kβ X-Ray emission spectroscopy detects non-covalent interactions of phosphate biomolecules in situ

2021 ◽  
Author(s):  
Zachary Mathe ◽  
Olivia McCubbin Stepanic ◽  
Sergey Peredkov ◽  
Serena DeBeer
Keyword(s):  
Nucleic Acids ◽  
Emission Spectroscopy ◽  
Adenine Nucleotides ◽  
X Ray ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Phosphate Groups

Phosphorus is ubiquitous in biochemistry, found in the phosphate groups of nucleic acids and the energy-transferring system of adenine nucleotides (e.g. ATP). Kβ X-ray emission spectroscopy (XES) at phosphorus has...

scholarly journals Evaluation of equilibrium constants for the interaction of lactate dehydrogenase isoenzymes with reduced nicotinamide-adenine dinucleotide by affinity chromatography

1975 ◽  
Vol 151 (3) ◽  
pp. 631-636 ◽  
Author(s):  
R I Brinkworth ◽  
C J Masters ◽  
D J Winzor
Keyword(s):  
Lactate Dehydrogenase ◽  
Affinity Chromatography ◽  
Equilibrium Constants ◽  
Mouse Tissue ◽  
Rabbit Muscle ◽  
Muscle Lactate ◽  
Sodium Phosphate Buffer ◽  
A Value ◽  
Series Of Experiments ◽  
Reduced Nicotinamide Adenine Dinucleotide

Rabbit muscle lactate dehydrogenase was subjected to frontal affinity chromatography on Sepharose-oxamate in the presence of various concentrations of NADH and sodium phosphate buffer (0.05 M, pH 6.8) containing 0.5 M-NaCl. Quantitative interpretation of the results yields an intrinsic association constant of 9.0 × 104M−1 for the interaction of enzyme with NADH at 5°C, a value that is confirmed by equilibrium-binding measurements. In a second series of experiments, zonal affinity chromatography of a mouse tissue extract under the same conditions was used to evaluate assoication constants of the order 2 × 105M−1, 3 × 105M−1, 4 × 105M−1, 7 × 105M−1 and 2 × 106M−1 for the interaction of NADH with the M4, M3H, M2H2, MH3 and H4 isoenzymes respectively of lactate dehydrogenase.

METABOLISM OF LEPTOSPIRES: II. THE ACTION OF 8-AZAGUANINE

1967 ◽  
Vol 13 (12) ◽  
pp. 1621-1629 ◽  
Author(s):  
Russell C. Johnson ◽  
Palmer Rogers
Keyword(s):  
Nucleic Acids ◽  
Ribonucleic Acid ◽  
Rna Synthesis ◽  
Inhibitory Effect ◽  
Relative Increase ◽  
Purine Biosynthesis ◽  
Low Concentrations

Both the pathogen Leptospira pomona and the saprophyte L. biflexa Patoc I can convert exogenous adenine, guanine, and 8-azaguanine to the corresponding nucleotide and incorporate them into nucleic acids. L. pomona is inhibited by low concentrations of 8-azaguanine (50 μg/ml) and this inhibition is associated with less than a 5% replacement of the ribonucleic acid (RNA) guanine residues by the analogue. Guanine possessed the highest activity for antagonizing the inhibitory effect of 8-azaguanine. The biosynthetic process of L. pomona most affected by the analogue was a relative increase in RNA synthesis. The analogue-resistant L. biflexa incorporated 1/10 as much 8-azaguanine as L. pomona. The higher rate of purine biosynthesis, in addition to the lesser amount of 8-azaguanine incorporated, may account for the analogue resistance of L. biflexa.

Effect of Temperature on Incubation Time for Spontaneous Morphology Change in Electrodeposited Copper Metallization

2005 ◽  
Vol 863 ◽  
Author(s):  
S. Ahmed ◽  
D.N. Buckley ◽  
S. Nakahara ◽  
Y. Kuo
Keyword(s):  
Incubation Period ◽  
Incubation Time ◽  
Annealing Time ◽  
Room Temperature ◽  
Diffusion Mechanism ◽  
Systematic Investigation ◽  
Effect Of Temperature ◽  
Copper Metallization ◽  
Morphology Change ◽  
A Value

AbstractA systematic investigation of the effect of annealing time and temperature on the incubation period for spontaneous morphology change (SMC) in electrodeposited copper metallization is reported. The incubation time is greatly reduced at higher temperatures. At each temperature, the remaining incubation time at room temperature was found to decrease approximately linearly with increasing annealing time. An Arhennius plot of the measured rates of decrease showed good linearity and yielded a value of 0.48 eV for the activation energy. This is consistent with a vacancy diffusion mechanism for the process occurring during the incubation period and supports our proposed mechanism for SMC.

Changes in the nucleic acid content of the uterus of sheep during involution following ovariectomy and following oestrogenic stimulation

1976 ◽  
Vol 27 (5) ◽  
pp. 669 ◽  
Author(s):  
DA Little ◽  
LJ Lambourne
Keyword(s):  
Nucleic Acid ◽  
Nucleic Acids ◽  
Ribonucleic Acid ◽  
Acid Content ◽  
Deoxyribonucleic Acid ◽  
Total Content ◽  
Mean Value ◽  
Nucleic Acid Content ◽  
Uterine Tissue ◽  
Rna Concentration

The concentrations of nucleic acids, deoxyribonucleic acid (DNA) and ribonucleic acid (RNA), in ovine uterine tissue were studied to determine whether the ratio RNA/DNA might be used in the bioassay of oestrogenic activity. As the uterus decreased in size with time after ovariectomy, the concentration of DNA increased markedly, but the total content of DNA in the uterus remained constant (mean value 342 ? 8 (SE) mg). The RNA concentration of the tissue decreased during involution, with the result that a highly significant reduction of 33% in the RNA/DNA ratio occurred within 2 weeks of ovariectomy. The ratio decreased further with time. Other ewes were treated for 3 days with diethylstilboestrol dipropionate (10 µg/day), commencing 2 weeks after ovariectomy; the stage of the oestrous cycle at which the ovaries were removed had no effect on the response to the oestrogen. Changes in the nucleic acid concentrations in the uteri of these ewes, and the results obtained during involution, indicate that the RNA/DNA ratio of uterine tissue in ovariectomized ewes has potential as a basis for the bioassay of materials of low oestrogenic potency.

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