Studies on the conformation of a-globulin from Sesamum indicum L. in cationic and nonionic detergents.

The circular dichroic spectra of a-globulin from Sesamum indicum L. was recorded in the presence of cetyltrimethyl ammonium bromide, Triton X-100 and Brij-36T. The protein in 0.2 Μ phosphate buffer pH 7.4 had about 25% β-structure and 5% α-helix, the rest being aperiodic or irregular structure and a-helix, structure was increased by cationic detergent cetyl trimethyl ammonium bromide. But, the increase in α-helix content was much less than that induced by an anionic detergent, sodium dodecyl sulphate. In non-ionic detergent like Brij-36T and Triton X-100, specific β-structures like II-β and I-β were formed along with changes in α-helical and aperiodic structures. These results suggest that the protein has a fairly labile quaternary structure.