Molecular-Sieve Chromatography of Proteins on Granulated Polyacrylamide Gels

Fawcett, J. S.; Morris, C. J. O. R.

doi:10.1080/01496396608049432

Cited by 165 publications

(40 citation statements)

References 16 publications

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“…A proposed radius size of 0.15 nm for the acrylamide fibers is rather small and may not reflect realistic features of the gel. In contrast to the present study of water diffusion, the previous research (65,27) investigated the transport properties of much larger proteins (1.6 -9 nm). It is therefore useful to consider other factors such as adsorption that may account for the decrease in the observed diffusion coefficients in gels.…”

Section: Figmentioning

confidence: 60%

“…In deriving this equation, Mackie and Meares (73) assumed that the obstacles, that is, lattice sites or polymer fibers in the present study, are of the same size as the solutes. Although, the polymer fiber size is expected to be larger (approximately 1-nm radius (65,27)) than that of the water molecule (radius equal to 0.15 nm), the model predicted water diffusion coefficients in gels fairly well. Therefore, the major problems with using the Mackie-Meares theory are that it fails to account for adsorption effects and that the validity of the assumption concerning the relative size of fibers to solute size is questionable.…”

Section: Figmentioning

confidence: 99%

“…Equation [27] can now be solved over the macroscopic sample domain and compared to the experimental values obtained from the NMR experiments as shown in the following section.…”

Section: Volume Averaging In V T and The One-equation Modelmentioning

confidence: 99%

“…Diffusive transport of large and small solutes in hydrogels has been studied by gel permeation chromatography (27)(28)(29), diffusion cells (30), light scattering (31,32,33), pulsed field gradient NMR (34 -37), and other methods (38). Diffusion of solutes in hydrogels is expected to depend upon the size of the probe relative to the size of the pore spaces in the gel, the geometry of the gel structure, and various physical/chemical interactions between the probe species and the gel matrix.…”

Section: Introductionmentioning

confidence: 99%

“…Diffusion of solutes in hydrogels is expected to depend upon the size of the probe relative to the size of the pore spaces in the gel, the geometry of the gel structure, and various physical/chemical interactions between the probe species and the gel matrix. In order to account for probe size, the Ogston theory has been extended to diffusion (and electrophoresis) (27,28,39) whereby the partition coefficient has been equated to the ratio of the diffusion coefficient in the gel to that in free solution. Other approaches, including hindered transport theory (40,41), have also been used to describe the effects of solute size on diffusion.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Proton Diffusion andT1Relaxation in Polyacrylamide Gels: A Unified Approach Using Volume Averaging

Penke

Kinsey

Gibbs

et al. 1998

Journal of Magnetic Resonance

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The structure of polyacrylamide gels was studied using proton spin-lattice relaxation and PFG diffusion methods. Polyacrylamide gels, with total polymer concentrations ranging from 0.25 to 0.35 g/ml and crosslinker concentrations from 0 to 10% by weight, were studied. The data showed no effect of the crosslinker concentration on the diffusion of water molecules. The Ogston-Morris and Mackie-Meares models fit the general trends observed for water diffusion in gels. The diffusion coefficients from the volume averaging method also fit the data, and this theory was able to account for the effects of water-gel interactions that are not accounted for in the other two theories. The averaging theory also did not require the physically unrealistic assumption, required in the other two theories, that the acrylamide fibers are of similar size to water molecules. Contrary to the diffusion data, T 1 relaxation measurements showed a significant effect of crosslinker concentration on the relaxation of water in gels. The model developed using the Bloch equations and the volume averaging method described the effects of water adsorption on the gel medium on both the diffusion coefficients and the relaxation measurements. In the proposed model the gel medium was assumed to consist of three phases (i.e., bulk water, uncrosslinked acrylamide fibers, and a bisacrylamide crosslinker phase). The effects of the crosslinker concentration were accounted for by introducing the proton partition coefficient, K eq , between the bulk water and crosslinker phase. The derived relaxation equations were successful in fitting the experimental data. The partition coefficient, K eq , decreased significantly as the crosslinker concentration increased from 5 to 10% by weight. This trend is consistent with the idea that bisacrylamide tends to form hydrophobic regions with increasing crosslinker concentration.

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Section: Figmentioning

confidence: 60%

Section: Figmentioning

confidence: 99%

“…Equation [27] can now be solved over the macroscopic sample domain and compared to the experimental values obtained from the NMR experiments as shown in the following section.…”

Section: Volume Averaging In V T and The One-equation Modelmentioning

confidence: 99%