Transfusion Gelatin Research Articles

Interaction of vanadium(V) oxoanions with ovalbumin and transfusion gelatin

Vanadate(V) anions have been found to modulate the activity of a large number of enzymes. To elucidate these interactions, a physico-chemical study of the binding of meta-vanadate(V) with two typical proteins ovalbumin and transfusion gelatin has been taken up. The binding has been investigated by polarographic method at pHs 7.5 and 9.3, and at 30°C. Values of intrinsic association constant, standard Gibb's free energy change, and the number of amino acids involved in these bindings are reported. Analysis of the binding sites has been done.

PH-Metric and Equilibrium Dialysis Studies on the Interaction of Surfactant Cations with Transfusion Gelatin

pH-Metric and Equilibrium Dialysis Studies on the Interaction of Surfactant Cations with Transfusion Gelatin

PH‐Metric and Equilibrium Dialysis Studies on the Binding of Mercuric Ions with Native and Modified Transfusion Gelatin

pH‐Metric and Equilibrium Dialysis Studies on the Binding of Mercuric Ions with Native and Modified Transfusion Gelatin

Polarographic studies on the binding of azo dyes with proteins

Polarographic studies on the binding of two anionic azo dyes, methyl orange and congo red, with two proteins, transfusion gelatin and ovalbumin, have been carried out. Phosphate buffer at three pH values, viz., 5.8, 7.2 and 8.0 was taken to study the pH effect on the binding. The value of id/(id)0 was found to increase with pH in each case showing complex formation between the dye and the protein. More binding was observed at low pH due to positive charge on the protein. The number of available binding sites and the values of the intrinsic association constants have been determined. The greater binding in the case of transfusion gelatin was due to the open structure and greater number of cationic groups in the former. Methyl orange, being a smaller molecule, approaches the binding sites more easily than congo red. The binding was found to be statistical in nature.

Polarographic studies on the binding of azo dyes with proteins

Summary Polarographic studies on the binding of two anionic azo dyes, methyl orange and congo red, with two proteins, transfusion gelatin and ovalbumin, have been carried out. Phosphate buffer at three pH values, viz. , 5.8, 7.2 and 8.0 was taken to study the pH effect on the binding. The value of i d /( i d ) 0 was found to increase with pH in each case showing complex formation between the dye and the protein. More binding was observed at low pH due to positive charge on the protein. The number of available binding sites and the values of the intrinsic association constants have been determined. The greater binding in the case of transfusion gelatin was due to the open structure and greater number of cationic groups in the former. Methyl orange, being a smaller molecule, approaches the binding sites more easily than congo red. The binding was found to be statistical in nature.

Interaction of detergents with transfusion gelatin

AbstractBinding of sodium dodecyl and octyl sulphate to transfusion gelatin has been studied at pH 7.7 by equilibrium dialysis. At lower detergent concentration the binding is statistical, whereas at higher concentrations the binding increases apparently without limit. This may be explained by assuming unfolding of the protein molecule with formation of detergent micelles around the binding sites.

Viscometric studies on the interaction of sodium dodecyl sulphate with transfusion gelatin

Interaction of sodium dodecyl sulphate with transfusion gelatin has been studied in low pH range by viscosity measurements. It was found that with the addition of sodium dodecyl sulphate to transfusion gelatin at pH's 2.0, 3.0 and 4.0 viscosity decreases until precipitation sets in. With further addition of sodium dodecyl sulphate precipitate redissolves. The decrease in viscosity is probably due to greater compactness of the protein molecules. The behaviour of isoelectric transfusion gelatin towards sodium dodecyl sulphate has been found to be markedly different.

Equilibrium dialysis and polarographic studies on the binding of molybdate anions with ovalbumin and transfusion gelatin

The binding of molybdate ions has been studied with ovalbumin and transfusion gelatin using polarographic and equilibrium dialysis techniques. The intrinsic association constants and the number of sites have been calculated from Scatchard plots. The values of the association constants ( K) have been found to be 3.2 × 10 3 (pH 5.57), 3.06 × 10 3 (pH 7.5) and 2.8 × 10 3 (pH 9.3) for transfusion gelatin and 3.38 × 10 3 (pH 5.57), 3.33 × 10 3 (pH 7.5) and 3.28 × 10 3 (pH 9.3) for ovalbumin. The number of sites available for binding with the molybdate ions is much less than the actual number of cationic groups, which are 10,9, 8 for transfusion gelatin and 8, 7, 6 for ovalbumin at pH-values of 5.57, 7.5 and 9.3 respectively. Statistical effects seem to be more pronounced at lower concentrations and electrostatic effects at higher molybdate ion concentrations.

Turbidimetric Studies on the Interaction of Tungstate and Molybdate with Transfusion Gelatin

Turbidimetric Studies on the Interaction of Tungstate and Molybdate with Transfusion Gelatin

Biuret reaction of transfusion gelatin. I. Spectrophotometric studies on the Interaction of Copper and Nickel with transfusion gelatin

AbstractAbsorption measurements of mixtures of copper‐transfusion gelatin and nickel‐transfusion gelatin were carried out with changing metal: protein ratio and at different pH‐values (10–12.4). The addition of minute quantities of protein to cupric chloride gave a violet colour, and gradually increasing amounts of protein brought a change in colour from violet to red. The violet complex absorbed maximum light at 550 mμ whereas red complex absorbed at 525 mμ. The shift in λ max. with a change in metal: protein ratio has been ascribed to the formation of various types of chelate structure during the copper‐transfusion gelatin biuret reaction. On the other hand nickel‐transfusion gelatin biuret reaction has been characterised by the formation of only one type of complex corresponding to the violet complex of copper. λ max. for nickel complex was found to lie in the vicinity of 430 mμ.

Spectrophotometric studies on the binding of Cr(iii) to bovine serum albumin

AbstractSpectrophotometric studies of mixtures containing Cr(iii) and bovine serum albumin were carried out to know the binding of chromic ion to the serum protein. Experiments performed at varying metal: protein ratio and at different pH values gave a maximum at 580 mμ. An inflexion was obtained in molar extinction coefficient‐pH curves at a pH value corresponding to the pK values of carboxyl groups. All these go to prove that the carboxyl groups are likely to be the Prinzipal sites through which the fixation of chromic ions have been affected. Experiments carried out in the neutral pH region gave no evidence regarding the binding of metal ions to the imidazole groups of bovine serum albumin. The lesser reactivity of bovine serum albumin in comparison with that of transfusion gelatin (previously studied) has been attributed to the lack of effective multipoint sites, due to its folded structure, so as to fix several chromium atom intramicellarly.

A study of the interaction of copper(II). zinc(II), and cadmium(II) with transfusion gelatin

The binding of copper, zinc, and cadmium with transfusion gelatin has been measured indirectly by observing the displacement of hydrogen ions from the acidic groups of transfusion gelatin. It is seen that the binding data obtained from pH measurements agree well with those obtained from equilibrium dialysis. Copper, zinc, and cadmium show the characteristic binding with the carboxyl groups in the pH range 3-5.5 for which the log K values are found to be 2.18, 1.87, and 1.96 respectively. Potentiometric titration data also indicate that the interaction is a competitive one, i.e. the metal ions compete with the hydrogen ions for common sites. The extent of copper and zinc binding increases with increase in pH, whereas cadmium binding remains unaffected. It is, therefore, concluded that copper and zinc combine with the imidazole groups also (log K values are 3.40 and 2.91 respectively), but cadmium fails to react with the imidazole groups.

Polarography of Cadmium Transfusion–Gelatin Mixtures

PROTEIN solutions, generally used as maxima suppressors in polarographic work, are known to cause abnormal decrease in the diffusion current of metal ions due to factors such as adsorption1,2, viscosity3 and metal protein interaction4–6. The effect of increasing concentration of serum albumin on the limiting current of cadmium ion has been systematically investigated by Tanford4, who explained the marked decrease in the current in view of cadmium-protein complex formation. Investigations in this direction have not, so far, been undertaken in the case of gelatin, although the latter has been most widely used as the maximum suppressor. To meet this end, transfusion gelatin, a modified product of bone gelatin, with its well-characterized nature (in terms of hydrogen ion equilibria7 and mol. wt.8) was chosen and the effect of factors like pH, metal and protein concentration on the limiting current of cadmium was investigated.

Spectrophotometric Studies on the Binding of Cr(iii) to Transfusion Gelatin

AbstractSpectrophotometric studies of mixtures containing Cr(iii) and transfusion gelatin were undertaken to know the binding of chromic ion to the protein. Experiments carried out between pH 3:7 and 5.8 had indicated the binding of the metal through the carboxyl groups of the protein. The extent of metal binding was found to be dependent upon metal‐protein ratio, maximum binding taking place in the ratio metal to protein as 42:1.

Polarographic and pH-metric studies on the interaction of lead with transfusion gelatin

Polarographic and- pH-metric studies of mixtures containing lead- nitrate and transfusion gelatin were undertaken to ascertain how plumbous ions were bound to the protein. Experiments carried out with varying concentrations of the reactants at a fixed ionic strength; and.under vaying pH conditions have shown the existence of a metal-protein complex in the pH range 3.7–5.57. Experiments carried out at a higher pH range (5.9–6.8) gave little or no evidence for the binding of lead to the imidazole groups. An alternative procedure, identical in principle with BJERRUM's method, was employed to calculate V m from the difference in hydrogen ion data in the presence and absence of metal. Evidence is presented for a one-to-one binding of plumbous ion to the carboxylate ion of transfusion gelatin, for which the intrinsic association constant was calculated as 1.87 and the free energy change of the combination as −2.593 kcal.

Spectrophotometric Investigation of the Binding of Nickel to Transfusion Gelatin

Spectrophotometric Investigation of the Binding of Nickel to Transfusion Gelatin

A spectrophotometric study of the binding of cobalt by transfusion gelatin

A spectrophotometric study of the binding of cobalt by transfusion gelatin

Polarographic studies on the interaction of copper with transfusion gelatin

The influence of the protein concentration, metal ion concentration and pH on the i d /( i d ) 0 values was studied by carrying out polarographic measurements in mixtures of cupric sulphate and transfusion gelatin. It was found that a decrease in the value took place with increase in protein concentration and pH, while the same behaviour was observed with decreasing concentration of Cu 2+. The latter effect has been attributed to the binding of Cu 2+ with transfusion gelatin. Evaluation of log K showed that the copper is more strongly bound to the amino than to the carboxyl group.

Hydrogen ion equilibria of transfusion gelatin

Hydrogen ion equilibria studies of transfusion gelatin carried out at different temperatures revealed the presence of 84 carboxyl, 23 amino, 3–8 imidazole and 43 guanidinium groups per 75·10 3 g of the protein. The results confirmed the values of amino acid analysis and also those obtained from observations of apparent heats of ionsation. T anford's equation was found in this case to be applicable only in the carboxyl region, ( W = 0.027). Further work regarding the interaction of cations, other than hydrogen ions, with transfusion gelatin is in progress.