scholarly journals Influence of Hydrogen Ion Concentrations on the Protein Mobility in Native-PAGE Buffers

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Janarthanan S ◽  
◽  
Ganesh A ◽  
Hilda K ◽  
Bhuvaragavan S ◽  
...  

The study demonstrates the effect of hydrogen ion concentrations (pH) of Tank Buffer (TB) and resolving gel buffer (RGB) in a native-PAGE system on protein samples. A pH range of 7.8 to 9.3 for RGB and 8.3 to 9.3 for TB were used. Proteins in the samples under native-PAGE at varying pH of RGB such as 7.8, 8.3 and 8.8 with pH of TB, 8.3 and 8.8 were resolved well. The total running time for the samples to reach the end of the dye front ranged between 2.30 h to 4.30 h at the above pH combinations. It was observed as 3.30 h as total running time under normal pH conditions (RGB, pH 8.8; TB, pH 8.3). At the same time, buffers at higher pH or the combination of extreme pH (7.8 vs. 9.3) in the buffers were not favored good protein mobility/resolution, and bands were diffused. Longer running time was observed in various combinations of pH of RGB and pH of TB with 18.00 h being a longest with a pH of 8.3 and 9.3 for RGB and TB, respectively. This indicated the importance of pH of electrophoresis buffers for ionization of various proteins for better separation.

1956 ◽  
Vol 34 (7) ◽  
pp. 969-981 ◽  
Author(s):  
Joan Crowther ◽  
A. E. R. Westman

The rates of hydrolysis of sodium tetrametaphosphate and tetraphosphate (in the presence of tetrametaphosphate) have been measured at 65.5 °C. over the pH range 2.5 to 13.3. Tetrametaphosphate anions hydrolyze to tetraphosphate which in turn hydrolyzes to triphosphate and orthophosphate and not to pyrophosphate. Thus the terminal oxygen bridges in the tetraphosphate and not the central one are attacked preferentially. The reactions were first order and acid catalyzed. The tetrametaphosphate hydrolysis was also base catalyzed with a minimum rate in solutions of pH approximately 7.5. The rate of hydrolysis of tetraphosphate was greater than triphosphate at the hydrogen ion concentrations studied. Hydrolysis of a sodium phosphate glass indicated that preferential attack on terminal oxygen bridges takes place also with higher polymers. However, trimetaphosphate is formed at the same time.


In 1913, I described a method for recording changes in hydrogen-ion concentrations in tissues, by means of a manganese dioxide electrode in combination with a calomel electrode (1). By this method it was shown that the acidity of muscle probably increased at the same time as, or slightly before, the tension increased, and that the acidity decreased as the muscle relaxed (2). In a paper, which appeared as this note was being prepared for publication, Ritchie states that he has been unable to detect a variation in acidity by the use of manganese dioxide electrodes. I am inclined to think that his failure is due to the injury to the muscles on insertion of wires into its substance. In my own experiments the wires rest on the surface of the muscle.


Author(s):  
Daniela Helena Guimarães Pelegrine ◽  
Maria Thereza Moraes Santos Gomes

Abstract This work showed the whey proteins solubility curves, according with temperature and pH conditions. The product constituted of a whey protein isolate obtained from cow milk (ALACENTM 895), acquired by New Zeland Milk Products Ltd. There is a straight analogy between fouling and protein unfolding when milk derived fluids are processed in equipments of heat exchangers, where whey proteins are unfolded in an irreversible way, exposing hidrophobic groups, and they become insoluble and form aggregates. An integrated study was conducted on the effects of temperature and pH on the solubility of whey proteins. The solubility was determined experimentally in the temperature range of 40-90 °C, and pH range of 5.0 - 6.8. The results showed that, both the temperature and pH influenced in the protein solubility; besides, the solubility values were minimum at the pH 4.0 for all temperature values. It was also observed that solubility decreased with temperature increased.


2018 ◽  
Vol 15 (30) ◽  
pp. 489-497
Author(s):  
J. T. B. SILVA ◽  
K. C. ROCHA ◽  
R. M. F. CUBA

With the progress in the agriculture sector, improper domains of pesticides, herbicides, and insecticides have grown, which have been negatively affected the environment until the present day. Therefore, the present work has as objective to evaluate the efficiency of the natural coagulant Tanfloc in the clarification stage with respect the herbicide glyphosate removal and the turbidity parameter by using jar test with different pH conditions and coagulant concentration. As a result, was obtained that for the pH range of 5-5.5 the natural coagulant has shown more efficient, with a glyphosate percentage removal of approximately 98.0% using low concentrations and turbidity removal of 21.69%. On the other hand, for the pH range of 6.8 to 7.3, the coagulant has not shown profitable results, considering that, for some concentrations, it was not possible to detect the herbicide removal. In the concentrations that were detected removal, the average glyphosate percentage removal was approximately 89% and an average of 20.24% of turbidity removal. In summary, although the natural coagulant has not shown remarkably efficient in the neutral pH range, the product may be considered an alternative device in water treatment with the respect of the use of metallic coagulants, which produce sludge with chemistry characteristics that may negatively affect the environment.


1964 ◽  
Vol 207 (1) ◽  
pp. 169-172 ◽  
Author(s):  
Oliver Carrier ◽  
Meredith Cowsert ◽  
John Hancock ◽  
Arthur C. Guyton

Isolated arterial segments, 1 cm in length and 0.5–1.0 mm in diameter, were perfused with Tyrode's solution titrated to various levels of pH. Po2, Pco2, and temperature were held at physiological levels; the perfusion pressure was held at 100 mm Hg, and flow was measured by a drop counter. There was a linear increase in flow as the pH was decreased from 7.4, 0.05 units at a time, with an increase of 87% obtained at pH 7.15. As the pH was further decreased, the flow dropped until at pH 6.8 it leveled off slightly above control level. When the pH was raised, there was an initial 35% decrease in flow by the time pH 7.50 was reached, followed by an increase, reaching 50% above control level at 7.65. At still higher pHs a precipitous decrease in conductance occurred, flow leveling off slightly below control level at pH 7.80. Consistent results were obtained on 45 vessels using Tyrode's solution titrated to the desired pH with lactic acid, hydrochloric acid, acetic acid, sulfuric acid, nitric acid, sodium hydroxides, or sodium bicarbonate. These results indicate that vessels have a very narrow pH range in which they maintain physiological tone.


2020 ◽  
Vol 8 (2) ◽  
pp. 286
Author(s):  
Nina Lackner ◽  
Andreas O. Wagner ◽  
Rudolf Markt ◽  
Paul Illmer

pH is a central environmental factor influencing CH4 production from organic substrates, as every member of the complex microbial community has specific pH requirements. Here, we show how varying pH conditions (5.0–8.5, phosphate buffered) and the application of a phosphate buffer per se induce shifts in the microbial community composition and the carbon flow during nine weeks of thermophilic batch digestion. Beside monitoring the methane production as well as volatile fatty acid concentrations, amplicon sequencing of the 16S rRNA gene was conducted. The presence of 100 mM phosphate resulted in reduced CH4 production during the initial phase of the incubation, which was characterized by a shift in the dominant methanogenic genera from a mixed Methanosarcina and Methanoculleus to a pure Methanoculleus system. In buffered samples, acetate strongly accumulated in the beginning of the batch digestion and subsequently served as a substrate for methanogens. Methanogenesis was permanently inhibited at pH values ≤5.5, with the maximum CH4 production occurring at pH 7.5. Adaptations of the microbial community to the pH variations included shifts in the archaeal and bacterial composition, as less competitive organisms with a broad pH range were able to occupy metabolic niches at unfavorable pH conditions.


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