title: Lanthanide-binding peptides with two pendant aminodiacetate arms: impact of the sequence on chelation.
abstract: Lanthanide complexes with a series of hexapeptides-incorporating two unnatural chelating amino acids with aminodiacetate groups, Ada(1) and Ada(2)-have been examined in terms of their speciation, structure, stability and luminescence properties. Whereas Ada(2) acts as a tridentate donor in all cases, Ada(1) may act as a tetradentate donor thanks to the coordination of the amide carbonyl function assisted by the formation of a six-membered chelate ring. The position of the Ada(1) residue in the sequence is demonstrated to be critical for the lanthanide complex speciation and structure. Ada(1) promotes the coordination of the backbone amide function to afford a highly dehydrated Ln complex and an S-shape structure of the peptide backbone, only when found in position 2.
authors.affiliation: INAC, Service de Chimie Inorganique et Biologique (UMR_E 3 CEA UJF), Commissariat à l'Energie Atomique, Grenoble, France.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Niedźwiecka
authors.forename: Federico
authors.initials: F
authors.lastname: Cisnetti
authors.forename: Colette
authors.initials: C
authors.lastname: Lebrun
authors.forename: Christelle
authors.initials: C
authors.lastname: Gateau
authors.forename: Pascale
authors.initials: P
authors.lastname: Delangle
mesh_terms: D000595:Amino Acid Sequence; D002614:Chelating Agents / Q000737:chemistry; D007098:Imino Acids / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry*; D017433:Protein Structure, Secondary
chemical_list: D002614:Chelating Agents; D007098:Imino Acids; D028581:Lanthanoid Series Elements; D010455:Peptides; C008109:iminodiacetic acid