scholarly journals The scattering of light in protein solutions. I—Gelatin solutions and gels

1930 ◽  
Vol 129 (811) ◽  
pp. 490-508 ◽  
Keyword(s):  
Analytical Data ◽  
Sedimentation Velocity ◽  
Sedimentation Equilibrium ◽  
Protein Solutions ◽  
Scattering Of Light ◽  
Molecular Weights ◽  
Protein Molecules ◽  
Long Time ◽  
And Diffusion

In a previous paper, the investigation of the scattering of light in agar sols and gels was described and a view regarding the changes taking place in the system during gelation was developed. In a series of paper, of which this is the first, the author proposes to publish investigations of the scattering of light in protein solutions. The various physical properties of the different proteins have been studied for a long time past. Several workers have tried to evaluate the molecular weights of the proteins from the osmotic pressure of their solutions and also from analytical data. Recently a very precise and definite method for the determination of the molecular weights of the proteins, based upon the sedimentation of these heavy molecules in the ultra-centrifuge, has been successfully developed by Svedberg. The molecular weight can be determined in two ways:—(I) by the measurement of the sedimentation equilibrium reached in the cell as a result of the centrifugal and diffusion forces; (II) by measuring the sedimentation velocity of the protein molecules in high centrifugal fields.

Simple determination of virus molecular weights by sedimentation equilibrium

1977 ◽  
Vol 81 (2) ◽  
pp. 447-449 ◽  
Author(s):  
Riva Rubinstein ◽  
Anthony C.H. Durham
Keyword(s):  
Sedimentation Equilibrium ◽  
Molecular Weights

THERMAL STABILITY OF THE NEW SOLITON TRANSPORTED BIO-ENERGY UNDER INFLUENCE OF FLUCTUATIONS OF CHARACTERISTIC PARAMETERS AT BIOLOGICAL TEMPERATURE IN THE PROTEIN MOLECULES

2005 ◽  
Vol 19 (32) ◽  
pp. 4677-4699 ◽  
Author(s):  
XIAO-FENG PANG ◽  
HUAI-WU ZHANG ◽  
JIA-FENG YU ◽  
YU-HUI LUO
Keyword(s):  
Energy Transport ◽  
Analytical Data ◽  
Dipole Interaction ◽  
Interaction Constant ◽  
Coupling Constant ◽  
Protein Molecules ◽  
Long Time ◽  
Higher Temperature ◽  
Davydov Model ◽  
Thermal Stability Of

The dynamic behaviors of the new soliton in the improved Davydov model in the protein molecules at biological temperature have been numerically simulated by utilizing the dynamic equations for the bio-energy transport and the Runge–Kutta way. In this simulation the influences of the temperature and structure disorders of the protein molecules on the soliton transporting the bio-energy have been completely considered. We find that the new soliton is quite stable in the cases of motion of a long time of 300 ps and of disorders of the structures of the proteins at biological temperatures of 300 K–320 K. The disorders of the structures contain the disorder of mass sequence of amino acids and the fluctuations of the coupling constant, force constant and dipole- dipole interaction constant and ground state energy of the proteins, designating the features of its structure and interactions between the particles in it. However, the soliton disperses in the cases of higher temperature of 325 K and larger structure disorders. The numerical results show that the new soliton is very robust against the influences of the thermal perturbation and structure disorders at biological temperature 300 K, its lifetime and critical temperature are at least 300 ps at 300 K and 320 K, respectively. These results are also consistent with analytical data.

scholarly journals The Isolation of Aggregates of Spectrin From Bovine Erythrocyte Membranes

1975 ◽  
Vol 28 (3) ◽  
pp. 259 ◽  
Author(s):  
GB Ralston
Keyword(s):  
Ionic Strength ◽  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Sedimentation Velocity ◽  
Sedimentation Equilibrium ◽  
Erythrocyte Membranes ◽  
Bovine Erythrocyte ◽  
Molecular Weights ◽  
Wide Range

Aggregated states of spectrin from bovine erythrocyte membranes can be detected in sedimentation velocity experiments. These aggregates have been isolated by means of gel filtration on columns of 4 % agarose. They appear to be stable over a wide range of pH and ionic strength, although they are dissociated by sodium dodecyl sulphate. Sedimentation equilibrium measurements yielded values of 960000 and 480000 for the molecular weights of the major aggregates, corresponding to a tetramer and dimer, respectively. The presence of different aggregated states in spectrin preparations may explain the wide variation in the reported physica~ properties of spectrin.

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