Polyvalent Anions Research Articles

INFLUENCE OF ELECTROLYTES ON STABILITY OF 0.2 MICRON DIAMETER POLYSTYRENE LATEX PARTICLES.

SummaryThe stability of polystyrene latex particles, 2000 A in diameter, in suspension, both uncoated and coated with human gamma globulin, was studied as a function of pH, electrolyte concentration and valence. Uncoated latex particle suspensions became unstable in the presence of polyvalent cations but not anions. When particles were coated with human gamma globulin, they acquired the characteristics of the protein coating, including its amphoteric properties. At pH 5.0 (net charge positive) the presence of polyvalent anions resulted in instability of the coated particles, while at pH 9.0 (net charge negative) the coated particles became unstable in the presence of polyvalent cations.

The Influence of Inorganic Salts on Plasma Antithrombin Activity

SummaryA study has been made of factors influencing the activities of plasma antithrombin. Optimal antithrombin activity was obtained between pH 7.8 and 8.5. Dialysis against distilled water reduced the antithrombin activity to less than 30 per cent of normal. The antithrombin activity was restored by the addition, directly or by dialysis, of a number of salts. The increased activity in the presence of the salts seemed to be a function of the polyvalent anions rather than of the ionic strength of the medium. The antithrombin activity of alpha- tocopherol phosphate in vitro appears to be a function of the phosphate ion and not of the vitamin itself.

The age-thickening of sweetened condensed milk: III. The effect of ions

SummaryAge-thickening of sweetened condensed separated milk can be greatly reduced by removing part of the diffusible salts by dialysis of the milk before processing. This treatment is still effective after high-temperature preheating, which indicates that denaturation of the whey proteins does not influence age-thickening independently of the milk salts.When added at the level of 20 m-equiv./kg of condensed milk to the milk before condensing, those polyvalent anions (phosphate, oxalate, citrate, ethylenediaminetetra- acetate) which have the property of forming undissociated or insoluble calcium salts greatly increase the rate of age-thickening. Fluoride, which forms an insoluble calcium salt but is monovalent, has the opposite effect.It is suggested that both natural and added polyvalent anions destabilize the condensed milk by forming linkages between the calcium atoms of the calcium caseinate micelles, producing the larger, more asymmetric units which were postulated in Part I to account for the viscosity changes during age-thickening. Fluoride would have the opposite effect by combining with the calcium, and so preventing such linkage formation by the polyvalent anions.When added to the milk at the same level as the anions, divalent cations, especially calcium and zinc, reduce the rate of age-thickening. It is suggested that this is due to removal of milk-serum anions, particularly phosphate and citrate, as insoluble or undissociated salts.The effect of both anions and cations added after condensing is almost the opposite of that produced by the same ion before condensing, with the exception that phosphate increases age-thickening in both cases. There is as yet no clear explanation for this observation.

Effect of unreabsorbed anions on proximal and distal transtubular potentials in rats.

Proximal and distal transtubular potential differences (ET) were measured in Na-fed and Na-depleted rats given infusions of 5% glucose in water, 0.9 m NaCl, 0.5 m NaHCO3, 0.5 m Na2SO4, and 0.25 m Na4Fe(CN)6. Proximal ET was –23.8 ± 0.8 mv and was uninfluenced by intravenous infusions of various Na+ salts. Distal ET was –53.8 ± 1.9 mv and rose sharply with infusions of Na+ salts of nonreabsorbable anions; the maximum rise was –31 mv in salt-depleted rats given Na2SO4. The rise in distal ET associated with polyvalent anions was attributed to both higher cation concentrations and lower Cl– concentrations in distal tubular fluid produced by infusions of these salts. It was suggested that the rise in distal ET is responsible for the known augmentation of K+ and H+ excretion produced by these salts.

Interaction of myosin A with ions

The interaction of myosin with ions has been investigated by several different methods. The preparation of salt-free myosin by gel filtration using dextran Sephadex G-50 is described. The solubility studies indicate that the precipitation of myosin at low ionic strength is a nonspecific ionic strength effect. The anion binding promotes the resolubilization of myosin. In solutions of strongly negative polyvalent anions (ADP/ ATP, PP, etc.) the precipitation of myosin does not occur, whereas in solutions of bivalent cations the zone of precipitation of myosin is extended. The molecular weight and the radius of gyration of the myosin molecule are not significantly affected by interaction with ions under conditions where myosin is fully soluble. It appears that ion binding influences the charge on the protein, as was confirmed by measurements of electrophoretic mobility of myosin in polyvalent anionic media. The influence of anions on the ATPase activity of myosin and the possible role of anion binding in the contractile process are discussed.

Specific Anion Effects with Antibenzoate Antibody

Summary Inorganic salts affect the binding of p-iodobenzoate by anti-p-azobenzoate antibody. The effects observed were due to the anion whereas the nature of the cation was unimportant. Except for fluoride, univalent anions decreased binding of p-iodobenzoate whereas nearly all of the polyvalent anions increased binding. The magnitude of the decrease for univalent anions was in the order CNS- > NO3- > I- > Br- > Cl-. It appears that the anions at high concentration compete with p-iodobenzoate for the antibody site if they are small enough to be accommodated in the site. It is proposed that the increase observed with polyvalent anions is due to increased ionic strength, which tends to decrease electrostatic repulsion between the negatively charged hapten and antibody; and that, in the case of univalent anions, this effect of ionic strength is more than overcome by direct competition with hapten for the antibody site. Further evidence for the presence of a positive charge in the antibody site of anti-p-azobenzoate antibody is given. The heat of reaction of p-iodobenzoate with antibody was determined from the temperature variation of the binding equilibrium constant to give a value of ΔH° = -4.1 ± 0.4 kcal/mole.

魚肉ねり製品の研究-VII

In the present paper, further evidences are presented which favor the previously offered view3) that the ability of water intake of a fish flesh retires to an extremity when the flesh is brought into contact with a salt solution of a certain definite ionic condition irrespective of the kind of salt which constitutes the solution. Using a flesh of sea-eel previously washed with water, the factor of water intake was determined for dilute salt solutions varied in concentration. The salts examined were sodium acetate, sodium oxalate and ammonium oxalate as examples of salt of organic acid, sodium bicarbonate and potassium monohydrogen phosphate, as examples of acid salt sodium pyrophosphate and sodium tripolyphosphate as examples of such acids as capable of liberating polyvalent anions. The results of the present experiment may be summarized as follows: i) The ability of water intake of fish flesh previously washed with water is depressed down to a minimum when the flesh is brought into contact with a dilute solution of any kind of salt examined, which satisfies a definite ionic condition. Thus, for a salt that undergoes m staged dissociations, the fish flesh is possible to form m numbering valleys of water intake. So far as salts consisting of ions of strong acid and base are concerned, attainment of a minimum of water intake is realized when ionic concentrations of the salt sodution satisfy the equation 1/2∑iViZi2×1/2∑i|Zi'|=0.1 where Vi stands for molar concentration of the i-th ion, Zi for the valency of the i-th ion set free in the solution when electrolytic dissociation of the salt has advanced to completion, while Zi' represents the valency of the i-th ion of the salt as existing in a certain intermediate stage of dissociation as a result of hydrolysis. In the case of a salt comprising an ion or ions of weak electrolyte, on the other hand, the relation of the above equation does not strictly hold, actual salt concentration that corresponds to a minimum of water intake shifting to a value 1.5-2 times as high as that calculated from said equation. ii) Phosphates (ortho-, pyro- and tripoly-phosphate) behave quite uniquely with regard to their influence upon the water intake of fish flesh. For instance, any one of their phosphates at a certain low concentration strongly depresses the water intake even in the presence of NaCl or KCl at a concentration of 1/2mol. It is worthy of note that the concentrations at which a phosphate causes a fish flesh to show valleys of water intake are senstively displaced with the lapse of time during which the fish flesh washed with water is kept out of contact with the phosphate solution; such a situation has never been met with in the case of any salts other than phosphates.

The correlation of ribonuclease activity with specific aspects of tertiary structure

Various physical parameters of bovine pancreatic ribonuclease and of some of its derivatives prepared by oxidation or reduction of disulfide bridges, methylation, and proteolytic digestion, have been investigated. Ultraviolet spectrophotometric measurements appear to establish a correlation between specific spectral properties of the materials and their enzymic activity. Viscometric and optical rotary studies, on the other hand, indicate that minor modifications in secondary structure may occur without detectable inactivation. Polyvalent anions and polyanions almost completely prevent the unfolding and spectral shift effect of 8 M urea, and of guanidium ions at concentrations between 1 and 3 M. These findings suggest that the full activity of ribonuclease, in the presence of such denaturing agents, is due to a refolding of the protein under the influence of ribonucleic acid.

Increasing the Washing Rate of Motion-Picture Films with Salt Solutions

Adsorbed thiosulfates may be effectively eliminated from films by the use of salt solutions. The salts may be employed in the wash water, as when washing with sea water, or as a separate bath previous to washing. The rate of elimination is largely controlled by the anion, and monovalent anions such as acetate and chloride are less effective than polyvalent anions such as sulfate, sulfite, phosphate and citrate. — These principles are incorporated in the Kodak Hypo Clearing Agent (K.H.C.A.). The effectiveness of this bath is most striking with films fixed in strongly hardening alum fixing baths and washed in cold water. Under these conditions, it is not unusual for the hypo to be reduced to 1% of that left by washing alone for equal periods. The results obtained when this product is applied to machine, spray, and rewind processing of motion-picture films, microfilms and aerial films are described. In general, savings are effected in both the time required and the water consumed, while very low levels of residual hypo are attained.

Hemagglutination by Col-MM-virus.

Summary1. Hemagglutination of sheep red blood cells by the Col-MM strain of the EMC virus was inhibited by polyvalent anions, the inhibitor titers (Hl-titers) of the different negative ions being roughly proportionate to their net electrical charge. 2. Whereas the HI-titer of specific antibody was inversely proportionate to the amounts of virus, indicating a stoichiometric combination of virus and antibody, the Hl-titers of sodium hexametaphosphate (6-valent anions) were only slightly influenced by the quantity of virus added. The order of mixing of the reactants was of great importance for the serum inhibition but without effect on the activity of hexametaphosphate. 3. The strong hemagglutination-inhibiting effect of sodium hexametaphosphate was not paralleled by any virus neutralizing activity. 4. A standard serological Hi-test, based on the results of a study of the Col-MM virus hemagglutination, is described. Applied on 569 human sera, this method gave a high incidence (12.5%) of strongly positive hem...

PERMEABILITY OF THE ERYTHROCYTE FOR ANIONS

A striking feature of the permeability of erythrocytes is the rapidity with which many anions enter and leave the cell. It is very probable that anion penetration is always an anion exchange across the membrane. Cation penetration either does not occur at all, or does so at such a slow rate that it cannot keep pace with the rapidly penetrating anion. Indeed the slow penetration of cations seems to occur only under conditions where there has been injury to the membrane of the cell [Jacobs and Parpart (7)]. The univalent inorganic anions (OH−, HCO3 −, Cl−, Br−, CN−, SCN−, NO3 −, I−) exchange across the membrane with great rapidity while polyvalent anions (e.g., SO4 −−, HPO4 −−) do so at a much slower rate [Jacobs (6), Mond and Gertz (10), Luckner and Lo-Sing (8), Dirken and Mook (4)]. A number of organic anions also appear to penetrate the red cells;...

Effects of a Divalent Cation on Sodium Removal from Intestinal Loops

In the presence of polyvalent cations sodium is absorbed from the intestine from concentrations much lower than the blood sodium level. The sodium concentration in the intestinal fluid may fall to as low as 5% of the blood level. Thus, the previously descrilml generalization that univalent anions move against high concentration gradients from intestine to blood when polyvalent anions ase present in the intestine, can be extended to include the comparable situation with regard to cations.

La diffraction des rayons X dans quelques solutions

Summary Previous work of the authors is confirmed and extended. In addition to the cases already reported of Th(NO 3 ) 4 and UO 2 (NO 3 ) 2 it appears that a “superarrangement” at least of the cations is present with: ThCl 4 UO 2 Cl 2 , La(NO 3 ) 3 , Cd(NO 3 ) 3 Zn(NO 3 ) 2 , Ni(NO 3 ) 2 , ZnCl 2 , ZnJ 2 , NiCl 2 . Moreover the polyvalent anions of Na 2 , WO 4 , Na 2 MoO 4 , H 2 PtCl 6 , HJO 4 , HClO 4 , H 2 SO 4 seem to show a superarrangement. With monovalent cations or anions no superarrangement could be found. A rule summarizing these results is given on page 1025. On the other hand HJO, was found to belong to the class with “gaseous distribution”. This was also the case with CdJ 2 in water and alcohol and with CdCl 2 , Hg(NO 3 ) 2 , Na 3 (PW 12 O 40 ), Ce 2 (SO 4 ) 3 , Zr(NO 3 ) 4 , in water. In these cases the diffraction pattern gives information on the inner structure of the molecules.

THE EFFECT UPON PERMEABILITY OF (I) THE SAME SUBSTANCE AS CATION AND ANION, AND (II) CHANGING THE VALENCY OF THE SAME ION

In a recent paper (I) facts were presented which indicate that polyvalent cations do not cause an increase in the resistance of Laminaria if they are combined with polyvalent anions, and it seems natural to suppose that the difference between the action of a salt with a bivalent cation and a monovalent anion, e.g., MgC12, and one with a bivalent cation and a bivalent anion, such as MgSO4, is due to the extra charge on the anion. Cations seem to cause an increase in resistance and anions a decrease. In MgC12 the action of the cation is dominant; in MgSO4, the action of the anion. If this effect is due to electrical charge, we may ask what will happen if the same ion is used as cation and as anion. This problem seems at first glance to present great difficulties because it is necessary to work with solutions which are not strongly acid or alkaline. Certain elements (such as aluminum, arsenic, chromium, etc.) exist both as cations and as anions, but they are very weak acids or bases and solutions of their salts are not neutral. The difficulty may be surmounted in a measure, however, by adding enough acid to the alkaline solution to bring its pH value down to that of the acid solution. If necessary the conductivity, may be increased by mixing with a neutral salt (e.g., NaCl). For this purpose, chromous chloride, sodium chromate, chromic acid, and sodium chloride were used. The chromous chloride is not soluble enough to make the conductivity equivalent to that of normal sea water, and in order that the osmotic pressure of the sea water (with which the solution is compared) should not be too low, the chromous chloride was mixed with sodium chloride. The final solution was then composed of 50 percent chromous chloride 0.6I M and 50 percent sodium chloride 0.52 M. This mixture has greater electrical resistance than sea water and has a pH of about 4.5 as determined by the hydrogen electrode. When tissue is transferred to tbis mixture from diluted sea water of the same conductivity, the following changes in resistance are observed (see fig. i, A): 464