Denaturation of proteins by surfactants studied by the Taylor dispersion analysis

July 28, 2017

Title

Denaturation of proteins by surfactants studied by the Taylor dispersion analysis

Author

Aldona Jelińska, Anna Zagożdżon, Marcin Górecki, Agnieszka Wisniewska, Jadwiga Frelek, Robert Holyst

Year

2017

Journal

PLoS ONE

Abstract

We showed that the Taylor Dispersion Analysis (TDA) is a fast and easy to use method for the study of denaturation proteins. We applied TDA to study denaturation of β-lactoglobulin, transferrin, and human insulin by anionic surfactant sodium dodecyl sulfate (SDS). A series of measurements at constant protein concentration (for transferrin was 1.9 x 10−5 M, for β- lactoglobulin was 7.6 x 10−5 M, and for insulin was 1.2 x 10−4 M) and varying SDS concentrations were carried out in the phosphate-buffered saline (PBS). The structural changes were analyzed based on the diffusion coefficients of the complexes formed at various surfactant concentrations. The concentration of surfactant was varied in the range from 1.2 x 10−4 M to 8.7 x 10−2 M. We determined the minimum concentration of the surfactant necessary to change the native conformation of the proteins. The minimal concentration of SDS for β-lactoglobulin and transferrin was 4.3 x 10−4 M and for insulin 2.3 x 10−4 M. To evaluate the TDA as a novel method for studying denaturation of proteins we also applied other methods i.e. electronic circular dichroism (ECD) and dynamic light scattering (DLS) to study the same phenomenon. The results obtained using these methods were in agreement with the results from TDA.

Instrument

J-815

Keywords

Circular dichroism, Secondary structure, Tertiary structure, Protein denaturation, Chemical stability, Biochemistry