title: Circular dichroic analysis of the secondary structure of myelin basic protein and derived peptides bound to detergents and to lipid vesicles.
abstract: In aqueous solution bovine myelin basic protein exhibits no significant alpha-helical or beta-pleated sheet structure. However, in vivo this protein is associated largely with the myelin membrane: experiments have therefore been performed to determine the structure of the protein when bound to lipid bilayers. Circular dichroism spectra show that this protein undergoes a major conformational change on binding to lipid bilayer vesicles formed from diacylphosphatidylserine or diacylphosphatidic acid, and on binding to micelles of several detergents. Association with diacylphosphatidylcholine failed to induce a structural change: this observation is interpreted in terms of an earlier report that lysophosphatidylcholine does increase the alpha-helical content of basic protein. These circular dichroism measurements and studies of the binding to the bilayer-forming lipids appear to provide support for significant hydrophobic lipid-protein interactions. Similar studies using two peptides produced by cleavf basic protein indicate that a major structure-forming region in the middle of the protein has been disrupted by this scission.
mesh_terms: D000818:Animals; D002417:Cattle; D055598:Chemical Phenomena; D002621:Chemistry; D002942:Circular Dichroism; D003902:Detergents; D008563:Membrane Lipids / Q000032:analysis*; D004676:Myelin Basic Protein / Q000032:analysis*; D010446:Peptide Fragments; D011485:Protein Binding; D011487:Protein Conformation
chemical_list: D003902:Detergents; D008563:Membrane Lipids; D004676:Myelin Basic Protein; D010446:Peptide Fragments