title: Distance between phosphine-sulfide sidechains of a disubstituted peptide by DRAMA 31P NMR.
abstract: Dipolar restoration at the magic angle (DRAMA) has been used to measure the 31P-31P internuclear distance between phosphine-sulfide substituted sidechanins on the fourth and eighth residues of a 12-residue helical peptide. The 7.4 A distance is the same for the peptide lyophilized in bulk or isolated in a cryo- and lyoprotected matrix of poly(ethylene glycol) and sucrose. However, the 31P linewidth for the undiluted peptide is an order of magnitude greater than for the matrix-isolated peptide indicating charge and hydration heterogeneity in the bulk state.
authors.affiliation: Department of Chemistry, Washington University, St. Louis, MO 63130, USA.
authors.forename: C A
authors.initials: CA
authors.lastname: Klug
authors.forename: D R
authors.initials: DR
authors.lastname: Studelska
authors.forename: G
authors.initials: G
authors.lastname: Chen
authors.forename: S R
authors.initials: SR
authors.lastname: Gilbertson
authors.forename: J
authors.initials: J
authors.lastname: Schaefer
mesh_terms: D055598:Chemical Phenomena; D002627:Chemistry, Physical; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D009842:Oligopeptides / Q000737:chemistry*; D010720:Phosphines / Q000737:chemistry*; D010758:Phosphorus; D017433:Protein Structure, Secondary; D013440:Sulfides / Q000737:chemistry*
chemical_list: D009842:Oligopeptides; D010720:Phosphines; D013440:Sulfides; D010758:Phosphorus