scholarly journals ION SERIES AND THE PHYSICAL PROPERTIES OF PROTEINS. I

1920 ◽  
Vol 3 (1) ◽  
pp. 85-106 ◽  
Author(s):  
Jacques Loeb

1. This paper contains experiments on the influence of acids and alkalies on the osmotic pressure of solutions of crystalline egg albumin and of gelatin, and on the viscosity of solutions of gelatin. 2. It was found in all cases that there is no difference in the effects of HCl, HBr, HNO3, acetic, mono-, di-, and trichloracetic, succinic, tartaric, citric, and phosphoric acids upon these physical properties when the solutions of the protein with these different acids have the same pH and the same concentration of originally isoelectric protein. 3. It was possible to show that in all the protein-acid salts named the anion in combination with the protein is monovalent. 4. The strong dibasic acid H2SO4 forms protein-acid salts with a divalent anion SO4 and the solutions of protein sulfate have an osmotic pressure and a viscosity of only half or less than that of a protein chloride solution of the same pH and the same concentration of originally isoelectric protein. Oxalic acid behaves essentially like a weak dibasic acid though it seems that a small part of the acid combines with the protein in the form of divalent anions. 5. It was found that the osmotic pressure and viscosity of solutions of Li, Na, K, and NH4 salts of a protein are the same at the same pH and the same concentration of originally isoelectric protein. 6. Ca(OH)2 and Ba(OH)2 form salts with proteins in which the cation is divalent and the osmotic pressure and viscosity of solutions of these two metal proteinates are only one-half or less than half of that of Na proteinate of the same pH and the same concentration of originally isoelectric gelatin. 7. These results exclude the possibility of expressing the effect of different acids and alkalies on the osmotic pressure of solutions of gelatin and egg albumin and on the viscosity of solutions of gelatin in the form of ion series. The different results of former workers were probably chiefly due to the fact that the effects of acids and alkalies on these proteins were compared for the same quantity of acid and alkali instead of for the same pH.

CrystEngComm ◽  
2020 ◽  
Vol 22 (11) ◽  
pp. 2031-2041
Author(s):  
Małgorzata Widelicka ◽  
Paweł Ławniczak ◽  
Adam Pietraszko ◽  
Katarzyna Pogorzelec-Glaser ◽  
Andrzej Łapiński

The physical properties of two proton conductors 1H-1,2,4-triazol-4-ium hydrogen oxalate (TriOX) and 1H-imidazol-3-ium hydrogen oxalate (ImiOX) were investigated.


1920 ◽  
Vol 2 (3) ◽  
pp. 273-296 ◽  
Author(s):  
Jacques Loeb

1. When a 1 per cent solution of a metal gelatinate, e.g. Na gelatinate, of pH = 8.4 is separated from distilled water by a collodion membrane, water will diffuse into the solution with a certain rate which can be measured by the rise of the level of the liquid in a manometer. When to such a solution alkali or neutral salt is added the initial rate with which water will diffuse into the solution is diminished and the more so the more alkali or salt is added. This depressing effect of the addition of alkali and neutral salt is greater when the cation of the electrolyte added is bivalent than when it is monovalent. This seems to indicate that the depressing effect is due to the cation of the electrolyte added. 2. When a neutral M/256 solution of a salt with monovalent cation (e.g. Na2SO4 or K4Fe(CN)6, etc.) is separated from distilled water by a collodion membrane, water will diffuse into the solution with a certain initial rate. When to such a solution alkali or neutral salt is added, the initial rate with which water will diffuse into the solution is diminished and the more so the more alkali or salt is added. The depressing effect of the addition of alkali or neutral salt is greater when the cation of the electrolyte added is bivalent than when it is monovalent. This seems to indicate that the depressing effect is due to the cation of the electrolyte added. The membranes used in these experiments were not treated with gelatin. 3. It can be shown that water diffuses through the collodion membrane in the form of positively charged particles under the conditions mentioned in (1) and (2). In the case of diffusion of water into a neutral solution of a salt with monovalent or bivalent cation the effect of the addition of electrolyte on the rate of diffusion can be explained on the basis of the influence of the ions on the electrification and the rate of diffusion of electrified particles of water. Since the influence of the addition of electrolyte seems to be the same in the case of solutions of metal gelatinate, the question arises whether this influence of the addition of electrolyte cannot also be explained in the same way, and, if this be true, the further question can be raised whether this depressing effect necessarily depends upon the colloidal character of the gelatin solution, or whether we are not dealing in both cases with the same property of matter; namely, the influence of ions on the electrification and rate of diffusion of water through a membrane. 4. It can be shown that the curve representing the influence of the concentration of electrolyte on the initial rate of diffusion of water from solvent into the solution through the membrane is similar to the curve representing the permanent osmotic pressure of the gelatin solution. The question which has been raised in (3) should then apply also to the influence of the concentration of ions upon the osmotic pressure and perhaps other physical properties of gelatin which depend in a similar way upon the concentration of electrolyte added; e.g., swelling. 5. When a 1 per cent solution of a gelatin-acid salt, e.g. gelatin chloride, of pH 3.4 is separated from distilled water by a collodion membrane, water will diffuse into the solution with a certain rate. When to such a solution acid or neutral salt is added—taking care in the latter case that the pH is not altered—the initial rate with which water will diffuse into the solution is diminished and the more so the more acid or salt is added. Water diffuses into a gelatin chloride solution through a collodion membrane in the form of negatively charged particles. 6. When we replace the gelatin-acid salt by a crystalloidal salt, which causes the water to diffuse through the collodion membrane in the form of negatively charged particles, e.g. M/512 Al2Cl6, we find that the addition of acid or of neutral salt will diminish the initial rate with which water diffuses into the M/512 solution of Al2Cl6, in a similar way as it does in the case of a solution of a gelatin-acid salt.


1927 ◽  
Vol 10 (6) ◽  
pp. 883-892 ◽  
Author(s):  
John H. Northrop

It is shown that by combining the osmotic pressure and rate of diffusion laws an equation can be derived for the kinetics of osmosis. The equation has been found to agree with experiments on the rate of osmosis for egg albumin and gelatin solutions with collodion membranes.


NANO ◽  
2019 ◽  
Vol 14 (11) ◽  
pp. 1950140
Author(s):  
Alaa M. Abd-Elnaiem ◽  
S. Moustafa ◽  
T. B. Asafa

Porous anodic alumina (PAA) thin films, having interconnected pores, were fabricated from Cu-doped aluminum films deposited on [Formula: see text]-type silicon wafers by anodization. The anodization was done at four different anodizing voltages (60[Formula: see text]V, 70[Formula: see text]V, 80[Formula: see text]V and 90[Formula: see text]V) in phosphoric acid and two voltages (60[Formula: see text]V and 70[Formula: see text]V) in oxalic acid. The aluminum and PAA samples were characterized by SEM and XRD while the pore arrangement, pore density, pore diameter, pore circularity and pore regularity were also analyzed. XRD spectra confirmed the aluminum to be crystalline with the dominant plane being (220), the Cu-rich phase have an average particle size of [Formula: see text][Formula: see text]nm uniformly distributed within the Al matrix of 0.4-[Formula: see text]m grain size. The steady-state current density through the anodization increased by 117% and 49% for oxalic and phosphoric acids, respectively, for 10[Formula: see text]V increase (from 60 to 70 V) in anodization voltage. Similarly, the etching rate increased by 100% for oxalic acid and by 40% for phosphoric acid which are responsible for 47% and 29% decreases in anodization duration, respectively. The highest value of circularity obtained for anodized Al–0.5[Formula: see text]wt.% Cu formed in oxalic acid at 60[Formula: see text]V was 0.86, and it was 0.80 for the phosphoric acid at 90[Formula: see text]V. Anodization of Al–0.5[Formula: see text]wt.% Cu films allows the formation of circular pores directly on [Formula: see text]-type silicon wafers which is of importance for future nanofabrication of advanced electronics. The results of anodized Al–0.5[Formula: see text]wt.% Cu thin film were compared with other anodized systems such as anodized pure Al and Al doped with Si.


1910 ◽  
Vol 12 (4) ◽  
pp. 487-509 ◽  
Author(s):  
Moyer S. Fleisher ◽  
Leo Loeb

1. In the experiments recorded in this paper the influence of the osmotic pressure of the blood upon absorption of fluid from the peritoneal cavity becomes apparent. Nephrectomy, removal of the adrenals, and other operations increase the osmotic pressure of the blood and increase the absorption of fluid from the peritoneal cavity. On the other hand, ether narcosis, at the period at which we tested its influence, causes neither an increase of osmotic pressure of the blood nor an increase in the absorption of fluid from the peritoneal cavity. 2. The increased osmotic pressure and increased absorption of fluid in nephrectomized animals is to a great extent not a specific effect of the removal of the kidneys, but approximately the same conditions can be observed after incisions of the skin and muscles. 3. After poisoning with uranium nitrate and in cases of peritonitis, complicating factors come into play, and under such conditions the absorption from the peritoneal cavity is not increased, notwithstanding the higher osmotic pressure of the blood. 4. In conditions in which the osmotic pressure of the blood is very high before the injection of sodium chloride solution into the peritoneal cavity (nephrectomized rabbits or rabbits injected with uranium nitrate three days previously), adrenalin causes no increase, or only a very slight one, in the absorption of peritoneal fluid. On the other hand, one day after the injection of uranium nitrate the osmotic pressure of the blood is only slightly increased before the injection of the sodium chloride solution into the peritoneal cavity, and here adrenalin causes a marked increase in absorption of fluid from the peritoneal cavity. 5. In animals injected with uranium nitrate the retention of sodium chloride and other osmotically active substances in the blood is not entirely due to interference with the functions of the kidney. This retention may be explained either by an inability of the tissues to bind the sodium chloride and other osmotically active substances or to a diminished permeability of the blood vessels for such substances. 6. While in nephrectornized animals the elimination of sodium chloride from the peritoneal cavity and also from the blood is increased, in animals injected with uranium nitrate such an elimination is diminished. This increase in the sodium chloride content of the peritoneal fluid in animals treated with uranium nitrate is accompanied by a decrease in the diffusion of other osmotically active substances into the peritoneal cavity. 7. While in nephrectomized animals and in animals injected with uranium nitrate one day previously, adrenalin causes a diminution of the fluid retained in the blood-vessels similar to the diminution noted in normal animals, adrenalin no longer exerts such an effect at a later stage of the uranium nitrate poisoning. At this period after the administration of uranium nitrate, the retention of fluid in the blood vessels is apparently equal in experiments with and without the injection of adrenalin, and following the absorption of fluid from the peritoneal cavity, the retention of fluid in the blood vessels in the uranium nitrate animals is increased comparatively to a greater extent than in normal animals. 8. Our experiments show a marked difference in the distribution of fluid and of osmotically active substances in nephrectomized animals and in animals injected with uranium nitrate. This difference may explain the much greater liability to the development of edema in animals injected with uranium nitrate.


1929 ◽  
Vol 23 (5) ◽  
pp. 1079-1089 ◽  
Author(s):  
John Marrack ◽  
Leslie Frank Hewitt
Keyword(s):  

1921 ◽  
Vol 3 (4) ◽  
pp. 547-555 ◽  
Author(s):  
Jacques Loeb

The experiments on casein solutions therefore confirm the conclusion at which we arrived from the behavior of gelatin and crystalline egg albumin that the forces determining the combination between proteins and acids or alkalies are the same forces of primary valency which also determine the reaction between acids and alkalies with crystalloids, and that the valency and not the nature of the ion in combination with a protein determines the effect on the physical properties of the protein.


1921 ◽  
Vol 3 (3) ◽  
pp. 391-414 ◽  
Author(s):  
Jacques Loeb

1. Ions with the opposite sign of charge as that of a protein ion diminish the swelling, osmotic pressure, and viscosity of the protein. Ions with the same sign of charge as the protein ion (with the exception of H and OH ions) seem to have no effect on these properties as long as the concentrations of electrolytes used are not too high. 2. The relative depressing effect of different ions on the physical properties of proteins is a function only of the valency and sign of charge of the ion, ions of the same sign of charge and the same valency having practically the same depressing effect on gelatin solutions of the same pH while the depressing effect increases rapidly with an increase in the valency of the ion. 3. The Hofmeister series of ions are the result of an error due to the failure to notice the influence of the addition of a salt upon the hydrogen ion concentration of the protein solution. As a consequence of this failure, effects caused by a variation in the hydrogen ion concentration of the solution were erroneously attributed to differences in the nature of the ions of the salts used. 4. It is not safe to draw conclusions concerning specific effects of ions on the swelling, osmotic pressure, or viscosity of gelatin when the concentration of electrolytes in the solution exceeds M/16, since at that concentration the values of these properties are near the minimum characteristic of the isoelectric point.


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