A calorimetric comparison of the interaction of sodium dodecyl sulfate with cytochrome c and erythrocyte glycoproteins.
The interactions of sodium dodecyl sulfate with cytochrome c and erythrocyte glycoproteins have been studied by the method of titration calorimetry. It was found that the initial addition of sodium dodecyl sulfate to cytochrome c caused an endothermic unfolding of the protein, detectable by circular dichroism (CD). This was followed by the exothermic binding of sodium dodecyl sulfate to the protein, without further CD-detectable conformational changes. In contrast, sodium dodecyl sulfate bound directly to the erythrocyte glycoproteins in an exothermic reaction without any accompanying CD-detectable conformation changes. This indicates that the glycoproteins solubilized in aqueous media have exposed hydrophobic regions which can interact directly with this detergent. The enthalpy changes and stoichiometries of binding are reported.
D002151:Calorimetry; D002942:Circular Dichroism; D003574:Cytochrome c Group; D004910:Erythrocyte Membrane / Q000378:metabolism; D004912:Erythrocytes / Q000378:metabolism; D006023:Glycoproteins / Q000097:blood*; D006801:Humans; D008565:Membrane Proteins; D011485:Protein Binding; D011487:Protein Conformation; D012967:Sodium Dodecyl Sulfate; D013816:Thermodynamics
D003574:Cytochrome c Group; D006023:Glycoproteins; D008565:Membrane Proteins; D012967:Sodium Dodecyl Sulfate