Effect of cetyl trimethyl ammonium bromide on the heat‐induced denaturation and protein‐protein interactions of arachin at pH 3.6

Abstract

The effect of a cationic detergent, cetyl trimethyl ammonium bromide, on the heat‐induced denaturation and protein‐protein interactions of arachin at pH 3.6 was studied by gel melting temperature, turbidity, electrophoresis, u.v. difference and fluorescence spectral measurements. Cetyl trimethyl ammonium bromide decreased the heat‐induced protein‐protein interactions as shown by the melting temperature, turbidity and electrophoretic measurements. Turbidity and electrophoretic measurements also showed that the detergent induces dissociation of the protein before and after heating it at higher detergent concentration (above 1 times 10‐3 M). U.v. difference and fluorescence spectral measurements suggested that the detergent induces unfolding of arachin at room temperature and this increases markedly after heating the protein in the detergent. The promotive effect of cetyl trimethyl ammonium bromide on the heat‐induced denaturation and its preventive effect on the protein‐protein interactions of arachin under the experimental conditions may arise out of the binding of the detergent to protein by primarily hydrophobic interactions.