Binding of dodecyl sulfate to proteins at high binding ratios. Possible implications for the state of proteins in biological membranes

A wide variety of proteins have been shown to bind identical amounts of an amphiphile, sodium dodecyl sulfate, on a gram per gram basis at monomer equilibrium concentrations above 0.5 mM. The binding is independent of ionic strength and primarily hydrophobic in nature. Only the monomeric form of the amphiphile binds to proteins, not the micellar form. The application of these results to models for biological membranes and to gel electrophoresis in sodium dodecyl sulfate is discussed.