Positive cooperative mechanistic binding of proteins at low concentrations: A comparison of poly (sodium N-undecanoyl sulfate) and sodium dodecyl sulfate

► We present a study of the interactions of SDS compared with a novel molecular micelle pSUS with four acidic proteins. ► pSUS binding follows a positive co-operative mechanistic binding to all the four proteins in the low concentration region. ► SDS binding is primarily negative cooperative. ► Protein surfactant interactions interactions are primarily hydrophobic and hence greater for pSUS. ► Protein separation in PAGE is achieved at concentrations 25 times less for pSUS, as compared to SDS.