title: A homobifunctional rhodamine for labeling proteins with defined orientations of a fluorophore.
abstract: The synthesis and characterization of a bifunctional rhodamine dye bearing 2-(iodoacetamido)ethyl substituents on the 3'- and 6'-nitrogen atoms is described. Aspects of the conversion of chloroacetamides to iodoacetamides are discussed, including a remarkably mild dehalogenation of an aromatic haloacetamide in the presence of NaI and camphorsulfonic acid. The bifunctional rhodamine has been designed for two-site, 1:1 labeling of proteins that contain two suitably disposed cysteine residues and is intended to constrain the orientation of the rhodamine absorption and emission dipoles in a predictable relationship to the protein structure.
authors.affiliation: National Institute for Medical Research, London, UK. j-corrie@nimr.mrc.ac.uk
authors.forename: J E
authors.initials: JE
authors.lastname: Corrie
authors.forename: J S
authors.initials: JS
authors.lastname: Craik
authors.forename: V R
authors.initials: VR
authors.lastname: Munasinghe
mesh_terms: D000081:Acetamides / Q000737:chemistry; D003432:Cross-Linking Reagents / Q000138:chemical synthesis* / Q000737:chemistry; D019281:Dimerization; D005456:Fluorescent Dyes; D007460:Iodoacetamide / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D011506:Proteins / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry*; D012974:Sodium Iodide; D013053:Spectrophotometry; D013141:Spiro Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D014966:Xanthenes / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: C112049:3',6'-bis(N-(2-(iodoacetamido)ethyl)-N-methylamino)spiro(isobenzofuran-1(3H)9'-(9H)xanthen)-3-one; D000081:Acetamides; D003432:Cross-Linking Reagents; D005456:Fluorescent Dyes; D011506:Proteins; D012235:Rhodamines; D013141:Spiro Compounds; D014966:Xanthenes; C013874:chloroacetamide; D012974:Sodium Iodide; D007460:Iodoacetamide