Conformation of β -endorphin and β -lipotropin: Formation of Helical Structure in Methanol and Sodium Dodecyl Sulfate Solutions

Circular dichroic spectra of camel β -endorphin and ovine β -lipotropin in water show little, if any, secondary structure. Intrinsic viscosities and sedimentation coefficients of the two peptides also suggest that the molecules are not compact and globular. Methanol or sodium dodecyl sulfate promotes the formation of helical structure to an extent as much as one-half of either peptide molecule. The conformation of the complex between camel β -endorphin and dodecyl sulfate may be related to the opiate-like function of this peptide hormone.