A new mode of size-dependent separation of proteins by capillary electrophoresis in presence of sodium dodecyl sulfate and concentrated oligomeric dextran.
Capillary electrophoresis in presence of sodium dodecyl sulfate (SDS) and 10% w/v of oligomeric dextran with molecular weight of just above 1000 was found to be an efficient medium for size-dependent separation of proteins (Karim, M. R., Janson, J.-C., Takagi, T., Electrophoresis 1994, 15, 1531-1534). The separations were found to be highly reproducible, both with respect to the position and relative amounts of the peaks. No evidence for a network structure in the medium could be found on examination of the effect of dextran concentration and viscosity measurements. The separation mechanism appears to be different from sieving by a polymer network structure. In free solution, SDS-protein complexes with molecular weights > 10,000 migrate with almost the same mobilities, irrespective of their molecular weight (this behavior is called free draining). Such SDS-complexes of proteins or peptides with molecular weights < 10,000, however, tend to increase their negatively signed mobilities with decreasing molecular weight (Karim, M. R., Shinagawa, S., Takagi, T., Electrophoresis 1994, 15, 1141-1146). Our working hypothesis is that in presence of the oligomeric dextran, the range of deviation from the free-draining electrophoretic behavior extends to higher molecular weights, resulting in a novel separation made.
Institute for Protein Research, Osaka University, Japan.
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D002942:Circular Dichroism; D003911:Dextrans / Q000494:pharmacology*; D019075:Electrophoresis, Capillary / Q000379:methods* / Q000706:statistics & numerical data; D046911:Macromolecular Substances; D008970:Molecular Weight; D011506:Proteins / Q000737:chemistry* / Q000302:isolation & purification*; D015203:Reproducibility of Results; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology*; D014783:Viscosity
D003911:Dextrans; D046911:Macromolecular Substances; D011506:Proteins; D012967:Sodium Dodecyl Sulfate