scholarly journals The sedimentation constant, diffusion constant and molecular weight of lactoglobulin

1949 ◽  
Vol 44 (1) ◽  
pp. 33-35 ◽  
Author(s):  
R. Cecil ◽  
A. G. Ogston
Keyword(s):  
Molecular Weight ◽  
Diffusion Constant ◽  
Sedimentation Constant ◽  
Constant Diffusion

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.

NOUVELLES DONNÉES SUR LE POIDS MOLÉCULAIRE DE LA GONADOTROPHINE DU SÉRUM DE JUMENT GRAVIDE

1960 ◽  
Vol XXXV (II) ◽  
pp. 221-224
Author(s):  
Roland Bourrillon ◽  
René Got
Keyword(s):  
Molecular Weight ◽  
Phosphate Buffer ◽  
Diffusion Constant ◽  
Sedimentation Constant

ABSTRACT Sedimentation constant of pregnant mares' serum gonadotrophin remains equal to 3.7 in water, phosphate buffer pH 7.3 and ClNa 0.1 m. But, diffusion constant, equal to 10.2 in water, becomes 4.2 in ClNa 0.1 m. Then, the molecular weight gets 68 500 instead of 28 000 in water.

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 CONCENTRATION AND PURIFICATION OF BACTERIOPHAGE

1938 ◽  
Vol 21 (3) ◽  
pp. 335-366 ◽  
Author(s):  
John H. Northrop
Keyword(s):  
Molecular Weight ◽  
Small Molecules ◽  
Specific Activity ◽  
Active Agent ◽  
Pure Substance ◽  
Solubility Curve ◽  
Denatured Protein ◽  
Sedimentation Constant ◽  
Rate Of Sedimentation ◽  
Living Organisms

1. A method for isolating a nucleoprotein from lysed staphylococci culture is described. 2. It is homogeneous in the ultracentrifuge and has a sedimentation constant of 650 x 10–13 cm. dyne–1 sec.–1, corresponding to a molecular weight of about 300,000,000. 3. The diffusion coefficient varies from about 0.001 cm.2/day in solutions containing more than 0.1 mg. protein/ml. to 0.02 in solutions containing less than 0.001 mg. protein/ml. The rate of sedimentation also decreases as the concentration decreases. It is suggested, therefore, that this protein exists in various sized molecules of from 500,000–300,000,000 molecular weight, the proportion of small molecules increasing as the concentration decreases. 4. This protein is very unstable and is denatured by acidity greater than pH 5.0, by temperature over 50°C. for 5 minutes. It is digested by chymo-trypsin but not by trypsin. 5. The loss in activity by heat, acid, and chymo-trypsin digestion is roughly proportional to the amount of denatured protein formed under these conditions. 6. The rate of diffusion of the protein is the same as that of the active agent. 7. The rate of sedimentation of the protein is the same as that of the active agent. 8. The loss in activity when susceptible living or dead bacteria are added to a solution of the protein is proportional to the loss in protein from the solution. Non-susceptible bacteria remove neither protein nor activity. 9. The relative ultraviolet light absorption, as determined directly, agrees with that calculated from Gates' inactivation experiments in the range of 2500–3000 Å. u. but is somewhat greater in the range of 2000–2500 Å. u. 10. Solubility determinations showed that most of the preparations contained at least two proteins, one being probably the denatured form of the other. Two preparations were obtained, however, which had about twice the specific activity of the earlier ones and which gave a solubility curve approximating that of a pure substance. 11. It is suggested that the formation of phage may be more simply explained by analogy with the autocatalytic formation of pepsin and trypsin than by analogy with the far more complicated system of living organisms.

FURTHER STUDIES ON THE PURIFICATION OF THROMBIN

1958 ◽  
Vol 36 (1) ◽  
pp. 603-611 ◽  
Author(s):  
Walter H. Seegers ◽  
Walter G. Levine ◽  
Robert S. Shepard
Keyword(s):  
Molecular Weight ◽  
Phosphate Buffer ◽  
Esterase Activity ◽  
Room Temperature ◽  
Specific Activity ◽  
Dry Weight ◽  
The Other ◽  
Resin Column ◽  
Sedimentation Constant ◽  
Single Symmetrical Peak

Purified biothrombin (bovine) was fractionated with the use of amberlite IRC-50 columns to obtain resin thrombin with an activity of 4100 units/mg. dry weight or 45,000 units/mg. tyrosine. As obtained from a resin column in 0.3 M phosphate buffer, pH 8.0, the thrombin is stable for 5 days at room temperature. At 4 °C. about 70% of the activity remains after 20 weeks. The maximum molecular weight is estimated by comparing with the specific activity (2000 units/mg.) and molecular weight (62,700) of purified prothrombin as follows: 2000/4100 × 62,700 or 30,600 as the probable molecular weight. Resin thrombin can lose its fibrinogen-clotting power while esterase activity is retained. On the other hand the esterase activity can be depressed without diminishing the clotting activity. Resin thrombin lyses fibrin. When examined in an ultracentrifuge a single symmetrical peak was found with a sedimentation constant of S = 3.9 (20 °C., 0.1 M KCl, 5.5 mg./ml.) Citrate thrombin was also fractionated with the use of IRC-50 to obtain material with a specific activity of 47,000 units/mg. tyrosine.

scholarly journals THE SIZE OF INFLUENZA VIRUS

1944 ◽  
Vol 79 (3) ◽  
pp. 267-283 ◽  
Author(s):  
W. M. Stanley
Keyword(s):  
Molecular Weight ◽  
Influenza Virus ◽  
High Molecular Weight ◽  
Particle Diameter ◽  
Allantoic Fluid ◽  
Sucrose Density Gradient ◽  
Chick Embryos ◽  
Sedimentation Behavior ◽  
Virus Activity ◽  
Sedimentation Constant

The sedimentation behavior of influenza virus in dilute solutions of electrolyte was found to be quite variable. At times the virus activity appeared to sediment at a rate comparable with that of particles about 80 to 120 mµ in diameter, at other times at a rate comparable with that of particles about 10 mµ in diameter, and at still other times the bulk of the activity appeared to sediment at a rate comparable with that of the larger particles and the residual activity at a rate comparable with that of the smaller particles. However, in the presence of a sucrose density gradient, the virus activity was always found to sediment with a rate comparable to that of particles about 80 to 120 mµ in diameter; hence it appeared that the variable sedimentation behavior in dilute electrolyte solution was due to convection or mechanical disturbances during centrifugation. About 30 per cent of the high molecular weight protein present in the allantoic fluid of chick embryos infected with the F 12 strain of influenza virus was found to consist of a component having a sedimentation constant of about 30 S, and hence a probable particle diameter of about 10 mµ. The residual protein of high molecular weight was present in the form of a component having a sedimentation constant of about 600 S, and hence a probable particle diameter of about 70 mµ. The proportion of the 30 S component in allantoic fluid of chick embryos infected with the PR8 strain of influenza virus was found to be considerably less. The 600 S and 30 S components of F 12 allantoic fluid were purified and separated by differential centrifugation. The purified preparations of the 600 S component were found to possess a specific virus activity from 100 to over 10,000 times that of the purified preparations of the 30 S component, the difference in activity apparently depending only on the degree of fractionation of the two components. The purified 30 S component was found to sediment normally in the presence of 12 per cent sucrose, whereas the small residual virus activity of such preparations was found to sediment in the presence of a sucrose density gradient with a rate comparable to that of much heavier particles. It is concluded that influenza virus activity is not associated with material having a particle diameter of about 10 mµ, but is associated solely with material having a sedimentation constant of about 600 S and hence a probable particle diameter of about 70 mµ.

scholarly journals THE MOLECULAR WEIGHT OF ANTIBODIES

1937 ◽  
Vol 65 (3) ◽  
pp. 393-414 ◽  
Author(s):  
Michael Heidelberger ◽  
Kai O. Pedersen
Keyword(s):  
Molecular Weight ◽  
Molecular Species ◽  
Principal Component ◽  
The Other ◽  
Type I ◽  
Egg Albumin ◽  
Type Iii ◽  
Sedimentation Constant ◽  
Other Hand ◽  
Immune Rabbit

1. Highly purified rabbit Type III pneumococcus anticarbohydrate proved to be homogeneous in the ultracentrifuge and its sedimentation constant, 7.0·10–13, did not differ from that of the principal component of normal rabbit globulin or of immune rabbit globulin containing up to 50 per cent of anti-egg albumin. The molecular weight of antibody in the rabbit is therefore probably very close to that of the principal normal globulin component, namely, 150,000. 2. Highly purified horse Type I pneumococcus anticarbohydrate, on the other hand, was only homogeneous in the ultracentrifuge when prepared from sera stored without preservative. Its sedimentation constant, 18.4·10–13, coincided with that of the principal globulin component in most of the Felton solutions and purified antibody solutions studied. The molecular weight of pneumococcus anticarbohydrate in the horse is probably three to four times that of the principal normal globulin component. 3. The significance of the differences between pneumococcus anticarbohydrate formed in the rabbit and in the horse is discussed. 4. Results are given of ultracentrifuge studies on the molecular species in solutions of egg albumin-anti-egg albumin specific precipitates dissolved in excess egg albumin. The implications of the results are discussed.

scholarly journals Thermo-physcial Properties and Characterization of TiO2 based Nanofluid Blended with Moringa Oleifera Oil

2021 ◽  
Author(s):  
RUBALYA VALANTINA S ◽  
Amsavahini S ◽  
Janani S ◽  
Monisha G
Keyword(s):  
Palm Oil ◽  
Moringa Oleifera ◽  
Vibrational Energy ◽  
Volume Fraction ◽  
Linear Equations ◽  
Diffusion Constant ◽  
Compositional Analysis ◽  
Industrial Applications ◽  
Quadratic Equation ◽  
Constant Diffusion

Abstract Nanoparticle TiO2 was synthesized by the co-precipitate method and was dispersed in palm oil blended with Moringa oleifera seed oil (Enriched palm oil-EPO). Structural and compositional analysis of TiO2 nanoparticles was carried out using SEM (Scanning Electron Microscope), XRD (X-Ray Diffraction) and FTIR analysis (Fourier Transform Infrared Spectroscopy). Using the analytical method, particle dimension, crystallite size by Debye Scherrer’s equation and vibrational energy of the molecule was investigated. Palm oil was blended with synthesised Moring oil to enhance its oxidative stability. TiO2 nanoparticles were dispersed at different volume fraction in EPO to analyse the temperature dependent physical properties. Bio-degradable lubricant nature of TiO2 based nanofluid was investigated by the variation of viscosity and density with temperature (30 to 60˚C). The amphiphilic properties of fatty acids in blended oils can contribute better lubrication compared to mineral oils. Experimented viscosity and density values with temperature was fitted to a non-linear equations, and was pragmatic that quadratic equation exhibits a best fit R2 > 0.999. Theoretical value of the viscosity was predicted using Einstein, Batchelor, and Wang mathematical model and was compared with the experimental value. Brownian motion of the particle in the oil was studied through the diffusion constant, diffusion time, and Brownian velocity. The present study could be used to synthesis nanofluid with desired volume fraction, viscosities and densities, so as work as a suitable bio degradable lubricant in many industrial applications.

scholarly journals PURIFICATION AND CRYSTALLIZATION OF DIPHTHERIA ANTITOXIN

1942 ◽  
Vol 25 (3) ◽  
pp. 465-485 ◽  
Author(s):  
John H. Northrop
Keyword(s):  
Molecular Weight ◽  
Ammonium Sulfate ◽  
Diphtheria Toxin ◽  
Soluble Fraction ◽  
Thin Plates ◽  
Fractional Precipitation ◽  
Protein Nitrogen ◽  
Sedimentation Constant ◽  
Diphtheria Antitoxin ◽  
Pure Protein

Purified preparations of diphtheria antitoxin have been obtained by digestion of the toxin-antitoxin complex with trypsin, followed by fractional precipitation with ammonium sulfate. The various fractions obtained in this way are all 90 per cent or more precipitated by diphtheria toxin but combine with different quantities of the toxin. The fraction precipitated between 0.33 and 0.5 saturated ammonium sulfate is homogeneous by electrophoresis and ultracentrifuge but does not have constant solubility. A small amount of a more soluble fraction has been obtained which does have constant solubility and satisfies the criteria of a pure protein. This protein crystallizes readily in poorly formed thin plates. It is very unstable and reverts to a less soluble non-crystallizable form. It has a sedimentation constant of 5.7 x 10–13 and a molecular weight of 90,500. It has an antitoxic value of 700–900 flocculation units per mg. protein nitrogen and has an antitoxic value by the protection test of about 700 units per mg. protein nitrogen. The precipitation range of the purified antitoxin with purified toxin is much wider than that with crude preparations.

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