Circular dichroism studies of sheep beta-lipotropic hormone.
The far ultraviolet circular dichroism spectra of sheep beta-lipotropic hormone (beta-LPH) were recorded under different conditions of pH, temperature, salt concentration, and solvent composition. Results confirm the stability of the hormone in strong basic or acidic solutions; moreover, temperatures up to 50 degrees C do not seem to affect noticeably the conformation of beta-LPH. However, increasing the NaC1 concentration or addition of dioxane in the solution brings about a conformational transition of the chain, interpreted as an increase in the helical content. The method of Yang (Chen, Y.H., Yang, J. T. & Martinez, H. M. (1972) Biochemistry 11, 4120-4131) was used to compute the proportion of helical, beta, and unordered forms of the hormone chain. The proportions are compared with those obtained from Fasman's predictive method (Chou, P. Y & Fasman, G. D. (1974) Biochemistry 13, 211-221 and Chou, P. Y. & Fasman, G. D. (1974) Biochemistry 13, 222-245) based on the known amino acid sequence of beta-LPH.
D000595:Amino Acid Sequence; D000818:Animals; D002942:Circular Dichroism; D004146:Dioxanes; D006863:Hydrogen-Ion Concentration; D009994:Osmolar Concentration; D011485:Protein Binding; D011487:Protein Conformation; D012756:Sheep; D013056:Spectrophotometry, Ultraviolet; D013696:Temperature; D008083:beta-Lipotropin
D004146:Dioxanes; D008083:beta-Lipotropin