title: Effect of sodium dodecyl sulfate, acid, alkali, urea and guanidine hydrochloride on the circular dichroism of alpha-globulin of Sesamum indicum L.
abstract: The circular dichrotic spectra of alpha-globulin have been obtained under various solution conditions of sodium dodecyl sulfate, acid, alkali, urea and guanidine hydrochloride. The protein in phosphate buffer pH 7.4, 0.2 M has about 25% beta-structure and 5% alpha-helix, the rest being aperiodic or irregular structure. Sodium dodecyl sulfate induced more alpha-helical structure in the protein. The protein had nearly 20% alpha-helix at 1 X 10(-2) M SDS. At extreme acid or alkaline pH, the protein had no alpha-helix with beta-structure decreasing with further extremes of pH. The protein is represented by 100% aperiodic structure in 6.6 M urea and in 6.0 M guanidine hydrochloride solutions. The above results are discussed in view of some of the earlier results with regard to the association-dissociation and denaturation behavior of alpha-globulin under various solution conditions.
mesh_terms: D000143:Acids / Q000494:pharmacology; D000468:Alkalies / Q000494:pharmacology; D000510:Alpha-Globulins / Q000302:isolation & purification / Q000378:metabolism*; D002942:Circular Dichroism; D006146:Guanidines / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D012639:Seeds / Q000378:metabolism*; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D014508:Urea / Q000494:pharmacology
chemical_list: D000143:Acids; D000468:Alkalies; D000510:Alpha-Globulins; D006146:Guanidines; D012967:Sodium Dodecyl Sulfate; D014508:Urea