THE DETERMINATION OF PARTIAL SPECIFIC VOLUMES BY DIFFERENTIAL SEDIMENTATION

1956 ◽  
Vol 34 (6) ◽  
pp. 809-814 ◽  
Author(s):  
W. G. Martin ◽  
W. H. Cook ◽  
C. A. Winkler
Keyword(s):  
Polyvinyl Alcohol ◽  
Sodium Alginate ◽  
Heavy Water ◽  
Specific Volume ◽  
Partial Specific Volume ◽  
Plasma Albumin ◽  
Bovine Plasma ◽  
Differential Sedimentation ◽  
Specific Volumes

Sedimentation in aqueous and heavy water solutions has been used to determine the partial specific volume of bovine plasma albumin, sodium alginate, and polyvinyl alcohol, resulting in 0.74 ± 0.01 (S.D.), 0.54 ± 0.06, and 0.79 ± 0.01 ml./gm. at 25 °C, respectively. The sedimentation method yields results comparable with those given by conventional methods for macromolecules.

PARTIAL SPECIFIC VOLUME MEASUREMENTS BY DIFFERENTIAL SEDIMENTATION

1959 ◽  
Vol 37 (10) ◽  
pp. 1662-1670 ◽  
Author(s):  
W. G. Martin ◽  
C. A. Winkler ◽  
W. H. Cook
Keyword(s):  
Heavy Water ◽  
Isotopic Exchange ◽  
Partial Specific Volume ◽  
Plasma Albumin ◽  
Bovine Plasma ◽  
Water Media ◽  
Volume Measurements ◽  
Differential Sedimentation ◽  
Specific Volumes ◽  
Magnetic Float

The partial specific volumes of several macromolecules were determined from their sedimentation rates in aqueous and heavy water solutions with results comparable to those obtained by conventional methods. Corrections for the changes in weight due to isotopic exchange were obtained from measurements on small quantities of material with a quartz spiral balance. Measurements of the partial specific volumes of bovine plasma albumin, polyvinyl alcohol, glycine, and triglycylglycine in both aqueous and heavy water media, made with a magnetic float apparatus, indicate that isotopic exchange has no significant effect on the macromolecular volume. The sedimentation method is therefore a micro method that does not require a knowledge of the concentration of macromolecules and which is applicable to mixtures that are resolvable during sedimentation.

scholarly journals Determination of partial specific volume and absolute concentration by densimetry

1984 ◽  
Vol 219 (3) ◽  
pp. 1049-1052 ◽  
Author(s):  
P H Stothart
Keyword(s):  
Absorption Coefficient ◽  
Neutron Scattering ◽  
Prior Knowledge ◽  
Small Angle ◽  
Specific Volume ◽  
Small Angle Neutron Scattering ◽  
Partial Specific Volume ◽  
Absolute Concentration ◽  
Non Destructive

The apparent partial specific volume, phi, of a protein (or other macromolecule) and the absolute concentration, c, can be determined from the densimetry of solutions and diffusates in 1H2O, 2H2O and 1H2O/2H2O mixtures if the ratios of concentrations (relative concentrations) are known. The densimetry method allows a non-destructive check on total macromolecule concentrations without prior knowledge of specific u.v.-absorption coefficient. The method may be especially useful in small-angle neutron-scattering studies.

Application of dn/dc Data for Determination of Partial Specific Volumes of Dissolved Macromolecules

1967 ◽  
Vol 40 (4) ◽  
pp. 1281-1295
Author(s):  
Wilfried Heller
Keyword(s):  
Specific Volume ◽  
Solution Process ◽  
Time Rate ◽  
Interpolation Procedure ◽  
Specific Volumes

Abstract The principles of a method are outlined whereby one can determine the partia specific volume of a solute, V, by means of measurements of dn/dc using a suitable pair of equations and a simple graphical interpolation procedure. The method yields V data which compare well with densitometrically obtained V data if the polarizability of both solvent and solute molecules is unaffected by the solution process. It is tested successfully on solutions of polystyrene in various solvents. The method appears to be particularly attractive for measurements of the change of V with temperature and also for conveniently following the time rate of changes in V such as during the coil → helix transition.

Binding Affinity of Purified Plasma Proteins for Phenethylbiguanide, an Oral Hypoglycemic Compound

1958 ◽  
Vol 4 (6) ◽  
pp. 496-509 ◽  
Author(s):  
Herndon G Shepherd ◽  
Hugh J McDonald
Keyword(s):  
Binding Affinity ◽  
Plasma Proteins ◽  
Equilibrium Dialysis ◽  
Colorimetric Method ◽  
Thermodynamic Activity ◽  
Plasma Albumin ◽  
Hypoglycemic Agent ◽  
Native Proteins ◽  
Bovine Plasma

Abstract A colorimetric method has been adapted to the quantitative determination of the oral hypoglycemic compound phenethylbiguanide. This method was useful in studying the binding affinity of purified bovine plasma albumin and gamma globulin for the hypoglycemic agent. Equilibrium dialysis studies, which measure the decrease in thermodynamic activity of the bound cation, reveal that there is no significant interaction between phenethylbiguanide and the two native proteins. Consequently, the two plasma proteins are assumed to exert no buffering action in controlling the plasma concentration of the drug. The adherence of phenethylbiguanide to Beer's Law indicates that the compound exists in the monomeric state in aqueous solution below 10-4 molar.

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