scholarly journals THE LS-ANTIGEN OF VACCINIA

1943 ◽  
Vol 77 (2) ◽  
pp. 155-164 ◽  
Author(s):  
Theodore Shedlovsky ◽  
Alexandre Rothen ◽  
Joseph E. Smadel
Keyword(s):  
Molecular Weight ◽  
Isoelectric Point ◽  
Specific Volume ◽  
Degradation Products ◽  
Diffusion Constant ◽  
Partial Specific Volume ◽  
Analytical Ultracentrifuge ◽  
Axis Ratio ◽  
Ellipsoidal Shape ◽  
Sedimentation Constant

Studies on LS-protein, the soluble double antigen of vaccinia, and on the degradation products L'S and L''S' have been made with electrophoresis and in the analytical ultracentrifuge. LS, which is homogeneous electrically and in the ultracentrifuge, has an isoelectric point at pH 4.8. At 4°C. its partial specific volume is 0.72 cc./gm., and its diffusion constant is 1.50 x 10–7 cm.2/sec. The sedimentation constant is 6.35 at 20°C., the molecular weight is 214,000, and the molecule appears to have an elongated ellipsoidal shape with an axis ratio of 1:20. L'S and L''S' are homogeneous electrically but not in the ultracentrifuge, L''S' being extremely polydisperse.

scholarly journals PURIFIED DIPHTHERIA ANTITOXIN IN THE ULTRACENTRIFUGE AND IN THE ELECTROPHORESIS APPARATUS

1942 ◽  
Vol 25 (3) ◽  
pp. 487-496 ◽  
Author(s):  
Alexandre Rothen
Keyword(s):  
Molecular Weight ◽  
High Activity ◽  
Isoelectric Point ◽  
Diffusion Constant ◽  
Enzymatic Treatment ◽  
Trypsin Digestion ◽  
Globulin Fraction ◽  
Sedimentation Constant ◽  
Diphtheria Antitoxin ◽  
Horse Plasma

Ultracentrifugation studies of diphtheria antitoxin showed that: 1. Purified antitoxin of high activity obtained from horse plasma without enzymatic treatment has exactly the same sedimentation constant as the globulin fraction obtained in a similar way from normal horse plasma s20water = 6.9 x 10–13. 2. Purified antitoxin obtained with trypsin digestion of the toxin-antitoxin complex has a sedimentation constant of s20water = 5.5 ± 0.1 x 10–13, a diffusion constant of D20water = 5.76 x 10–7, and a molecular weight of about 90,000. Electrophoresis experiments demonstrated that: 1. The trypsin-purified antitoxin has an isoelectric point not far from pH 7.0. 2. The reversible spreading noticed at about pH 7.3 cannot be attributed to heterogeneous preparation. 3. The large increase in the γ-globulin fraction occurring during immunization consists either of antitoxin of various degrees of activity or of some inert protein in addition to the antitoxin.

scholarly journals THE MOLECULAR WEIGHT AND ISOELECTRIC POINT OF THYROGLOBULIN

1935 ◽  
Vol 19 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Michael Heidelberger ◽  
Kai O. Pedersen
Keyword(s):  
Molecular Weight ◽  
Isoelectric Point ◽  
Specific Volume ◽  
Sedimentation Equilibrium ◽  
Sedimentation Constant ◽  
Diffusion Constants ◽  
Equilibrium Data ◽  
Round Numbers ◽  
And Diffusion

1. The sedimentation constant of hog thyroglobulin is 19.2ċ10–13. That of human thyroglobulin is essentially the same. 2. The specific volume of hog thyroglobulin is 0.72. 3. The isoelectric point of native hog thyroglobulin is at pH 4.58, that of denatured thyroglobulin at pH 5.0. 4. The molecular weight of hog thyroglobulin is, in round numbers, 700,000, as calculated from the sedimentation and diffusion constants, or 650,000, as calculated from the sedimentation equilibrium data. 5. The thyroglobulin molecule deviates markedly from the spherical.

Bestimmung des Molekulargewichtes der 20-β-Hydroxy-steroid-dehydrogenase

1962 ◽  
Vol 17 (7) ◽  
pp. 432-436 ◽  
Author(s):  
Matatiahu Gehatia
Keyword(s):  
Molecular Weight ◽  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Specific Volume ◽  
Sedimentation Coefficient ◽  
Partial Specific Volume ◽  
Hydroxy Steroid ◽  
Steroid Dehydrogenase

The enzyme 20-β-Hydroxy-steroid-dehydrogenase obtained from the culture of Streptomyces hydrogenans and dissolved in 0.05 M Tris puffer, pH 7.3, has been investigated by means of a ultracentrifuge at 20 °C. The sedimentation- as well as the diffusion-coefficients obtained from various solutions at different concentrations were extrapolated to the concentration c = 0. The resulting zero-value for the sedimentation coefficient is s0 = 6.64 s and for the diffusion coefficient is D0 = 5.51 × 10-7 cm2/sec. Supposing the partial specific volume of the enzyme under consideration analogously to other similar proteins is V+=0.749 ml/g, the molecular weight has been estimated as M = 118 400.

Physikalische und chemische Untersuchungen am broad bean mottle-Virus

1961 ◽  
Vol 16 (12) ◽  
pp. 786-791 ◽  
Author(s):  
H. L. Paul
Keyword(s):  
Molecular Weight ◽  
Broad Bean ◽  
Uv Light ◽  
Diffusion Constant ◽  
Aromatic Amino Acids ◽  
Mottle Virus ◽  
Partial Specific Volume ◽  
Absorption Data ◽  
Broad Bean Mottle Virus ◽  
Maximum Turbidity

Broad bean mottle virus (BBMV) contains 15.2 percent N and 1.83 percent P; the N/P ratio is 8.4 ± 0.3. The protein of BBMV contains 15.6 percent N and no P; the NA has a N/P ratio of about 1.85. From these data a NA content of about 22 percent can be evaluated. This value agrees with that of 23 percent obtained by orcinol reactions.The sedimentation constant at infinite dilution is 83 ± 2 S, the diffusion constant 1.44 ± 0.04 · 10-7 cm2/sec, and the partial specific volume 0.75 cm3/gram. From these data a molecular weight of 5.6 ± 0.5 millions for the unhydrated particles can be calculated. The diameter of these particles is about 24 mµ, which agrees fairly well with determinations made with the electron microscope 1. Estimations of molecular weight and diameter of the hydrated particles reveal about 10 millions and about 30 mu respectively.Purified BBMV was stable in neutral buffer solutions at 3 °C for some weeks and remained infective. Exhaustive dialysis of such virus suspensions against dist. water caused a considerable increase in turbidity, and, later on, precipitation of the virus. It was not possible to resuspend this virus completely by adding neutral buffer or salt solutions. Density gradient centrifugations showed these resuspensions to be inhomogeneous, whereas non-dialyzed virus suspensions in buffer gave only one narrow zone in the gradient tubes, indicating the homogeneity of the particles.In buffers of different pH , virus suspensions showed a maximum turbidity at about pH 4.5. For precipitations of BBMV with ammonium sulfate, higher salt concentrations were necessary than for most other viruses.The UV light absorption (corrected for light scattering) of BBMV as well as of its protein and its NA was measured. It could be shown that the absorption coefficient of BBMV protein is much lower than that of most other viruses, presumably because of the low content of aromatic amino acids as determined by chemical analysis recently 2.The estimation of the NA content of BBMV from UV absorption data is discussed.

Effect of molecular weight on the partial specific volume of polystyrenes in solution

Polymer ◽  
1974 ◽  
Vol 15 (10) ◽  
pp. 618-625 ◽  
Author(s):  
Jeanne François ◽  
Françoise Candau ◽  
Henri Benoit
Keyword(s):  
Molecular Weight ◽  
Specific Volume ◽  
Partial Specific Volume

PURIFICATION AND SOME PROPERTIES OF AUTOPROTHROMBIN C

1963 ◽  
Vol 41 (4) ◽  
pp. 1047-1063 ◽  
Author(s):  
Walter H. Seegers ◽  
Edmond R. Cole ◽  
Charles R. Harmison ◽  
Ewa Marciniak
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Diffusion Constant ◽  
Partial Specific Volume ◽  
Glycerol Solution ◽  
Plasma Antibody ◽  
Autoprothrombin C ◽  
Single Plasma ◽  
Physicochemical Measurements

Methods were developed for the isolation of autoprothrombin C, which is the second enzyme obtained from purified bovine prothrombin. In the presence of lipids and standardized conditions 0.35 μg of the purified autoprothrombin C were sufficient for clotting recalcified plasma in 15 seconds. Some physicochemical properties are as follows: S20, w is 2.27S, the diffusion constant 8.4 × 10−7 cm2/second, and the partial specific volume 0.695. The molecular weight from physicochemical measurements was 21,500. All amino acids were found, but only 1 molecule of methionine. On the basis of amino acid composition the molecular weight was found to be 27,000, giving an average of 24,200 for our two determinations. Prothrombin contains sufficient of each amino acid residue to supply autoprothrombin C and thrombin. Autoprothrombin II, however, has only sufficient amino acids for either autoprothrombin C or thrombin, but not both. The purified autoprothrombin C contained 7% carbohydrate (orcinol) and 3.8% hexosamine. It was stable at pH 7.2 for more than a week at room temperature, and longer in subzero glycerol solution. Autoprothrombin C was used to obtain a single precipitin band in agar diffusion plates with antibody to prothrombin. The band also identified with a single plasma antibody.

PURIFICATION AND SOME PROPERTIES OF AUTOPROTHROMBIN C

1963 ◽  
Vol 41 (1) ◽  
pp. 1047-1063 ◽  
Author(s):  
Walter H. Seegers ◽  
Edmond R. Cole ◽  
Charles R. Harmison ◽  
Ewa Marciniak
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Diffusion Constant ◽  
Partial Specific Volume ◽  
Glycerol Solution ◽  
Plasma Antibody ◽  
Autoprothrombin C ◽  
Single Plasma ◽  
Physicochemical Measurements

Methods were developed for the isolation of autoprothrombin C, which is the second enzyme obtained from purified bovine prothrombin. In the presence of lipids and standardized conditions 0.35 μg of the purified autoprothrombin C were sufficient for clotting recalcified plasma in 15 seconds. Some physicochemical properties are as follows: S20, w is 2.27S, the diffusion constant 8.4 × 10−7 cm2/second, and the partial specific volume 0.695. The molecular weight from physicochemical measurements was 21,500. All amino acids were found, but only 1 molecule of methionine. On the basis of amino acid composition the molecular weight was found to be 27,000, giving an average of 24,200 for our two determinations. Prothrombin contains sufficient of each amino acid residue to supply autoprothrombin C and thrombin. Autoprothrombin II, however, has only sufficient amino acids for either autoprothrombin C or thrombin, but not both. The purified autoprothrombin C contained 7% carbohydrate (orcinol) and 3.8% hexosamine. It was stable at pH 7.2 for more than a week at room temperature, and longer in subzero glycerol solution. Autoprothrombin C was used to obtain a single precipitin band in agar diffusion plates with antibody to prothrombin. The band also identified with a single plasma antibody.

scholarly journals Studies on Polydisperse Systems Using an Air-Driven Ultracentrifuge: Application to Phosphatidylcholine Vesicles

1979 ◽  
Vol 32 (2) ◽  
pp. 187 ◽  
Author(s):  
RG Clarke ◽  
GR Eagle ◽  
GJ Howlett
Keyword(s):  
Molecular Weight ◽  
Specific Volume ◽  
High Speed ◽  
Theoretical Calculations ◽  
Analytical Ultracentrifuge ◽  
Solution Density ◽  
Good Agreement

A high-speed air-driven ultracentrifuge (Airfuge) has been used to determine the molecular weight and effective specific volume of phosphatidylcholine vesicles. The method used to determine the effective specific volume involved varying the solution density until zero sedimentation of the vesicles occurred. The value obtained for the effective specific volume of 0�9885 mlJg agrees well with previously reported values. The determination of the molecular weight of the vesicles is based on a method in which the fraction of vesicles remaining in an upper fraction of the solution column is compared with the values obtained using standard proteins. The values obtained for the molecular weight of the vesicles range from 1� 7 x 106 to 2�3 X 106 and are in good agreement with results obtained using the analytical ultracentrifuge and with previously reported results. Possible effects due to the polydispersity of the solute are assessed using theoretical calculations and the possibility of using the Airfuge for the study of other polydisperse systems is discussed.

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