title: Circular dichroism studies of human big-endothelin-1 (Big ET-1).
abstract: The circular dischroism (CD) spectra of human endothelin (ET-1) and its precursor (Big ET-1) have been compared in order to provide information on the secondary structure of Big ET-1. It appears that the secondary structures of the common parts of the two molecules are very similar and that the additional C-terminal residues in Big ET-1 may contain both helical and sheet components, information which may be of use in modeling studies of the Big ET-1 structure. In studies of the pH dependence of the conformation of Big ET-1, it was found that Big ET-1 adopts similar structures at pH 6.0 and 7.0, but has a subtly different conformation at pH 8.0 that may result in a reduced susceptibility to proteolysis at this pH. This difference may be in the conformation of a turn-type structure, producing a less accessible peptide bond in the molecule at the site of cleavage.
authors.affiliation: Department of Crystallography, Birkbeck College, University of London, UK. ubcg91c@ccs.bbk.ac.uk
authors.forename: B A
authors.initials: BA
authors.lastname: Wallace
authors.forename: R
authors.initials: R
authors.lastname: Corder
mesh_terms: D002942:Circular Dichroism; D019332:Endothelin-1 / Q000737:chemistry*; D016232:Endothelins / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D011498:Protein Precursors / Q000737:chemistry*; D017433:Protein Structure, Secondary
chemical_list: D019332:Endothelin-1; D016232:Endothelins; D011498:Protein Precursors