title: Uranyl-peptide interactions in carbonate solution with DAHK and derivatives.
abstract: Metal-peptide complexes in a 1:1 ratio between the uranyl cation (UO2(2+)) and the peptides, DAHK or GGH, are observed in the gas phase (ESI-MS). Solution state studies with the same peptides and variants, DGHG, AcDGHG, and DAHKSE-CONH2, indicate that peptide-carboxylato donors can coordinate to the uranyl biscarbonato complex. UV-vis and fluorescence spectra of uranyl carbonate exhibit significant changes or quenching upon addition of peptide. NMR titration data were used to determine conditional association constants, log K = 2.2+/-0.4 and log K = 3.1+/-0.4, for the [UO2(CO3)2(GGH)] and [UO2(CO3)2(DAHK)] species, respectively. Uranyl asymmetric stretching frequencies for uranyl/ DAHKSE-CONH2 (v3 = 914 cm(-1)) and uranyl/DAHK (v3 = 908 cm(-1)) complexes and other infrared spectral features are also consistent with peptide-carboxylato coordination.
authors.affiliation: Department of Chemistry, University of Missouri-Kansas City, Kansas City, Missouri 64110, USA.
authors.forename: Huan
authors.initials: H
authors.lastname: Huang
authors.forename: Shveta
authors.initials: S
authors.lastname: Chaudhary
authors.forename: J David
authors.initials: JD
authors.lastname: Van Horn
mesh_terms: D002254:Carbonates / Q000737:chemistry*; D004347:Drug Interactions; D008956:Models, Chemical; D009842:Oligopeptides / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared; D013056:Spectrophotometry, Ultraviolet; D017974:Uranium Compounds / Q000737:chemistry
chemical_list: D002254:Carbonates; D009842:Oligopeptides; D010455:Peptides; D017974:Uranium Compounds; C431583:aspartyl-alanyl-histidyl-lysine