title: Deep-red fluorescent imaging probe for bacteria.
abstract: A versatile deep-red fluorescent imaging probe is described that is comprised of a bis(zinc(II)-dipicolylamine) targeting unit covalently attached to a pentamethine carbocyanine fluorophore with Cy5-like spectroscopic properties. A titration assay based on fluorescence resonance energy transfer is used to prove that the probe selectively associates with anionic vesicle membranes whose composition mimics bacterial cell membranes. Whole-body optical imaging experiments show that the probe associates with the surfaces of both Gram-positive and Gram-negative bacteria cells, and it can target the site of bacterial infection in a living mouse. In vivo accumulation at the infection site and subsequent clearance occurs more quickly than a structurally related near-infrared bis(zinc(II)-dipicolylamine) probe. The fact that the same deep-red probe molecule can be used for spectroscopic assays, cell microscopy, and in vivo imaging studies, is an important and attractive technical feature.
authors.affiliation: Department of Chemistry and Biochemistry, University of Notre Dame, Notre Dame, IN 46556, USA.
authors.forename: Alexander G
authors.initials: AG
authors.lastname: White
authors.forename: Brian D
authors.initials: BD
authors.lastname: Gray
authors.forename: Koon Yan
authors.initials: KY
authors.lastname: Pak
authors.forename: Bradley D
authors.initials: BD
authors.lastname: Smith
mesh_terms: D000818:Animals; D001424:Bacterial Infections / Q000175:diagnosis; D005456:Fluorescent Dyes / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D008164:Luminescent Proteins / Q000737:chemistry / Q000378:metabolism; D051379:Mice; D009942:Organometallic Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D010848:Picolinic Acids / Q000138:chemical synthesis* / Q000737:chemistry / Q000378:metabolism*; D012995:Solubility; D014867:Water / Q000737:chemistry; D000097573:Red Fluorescent Protein
chemical_list: D005456:Fluorescent Dyes; D008164:Luminescent Proteins; D009942:Organometallic Compounds; D010848:Picolinic Acids; D014867:Water; D000097573:Red Fluorescent Protein; C529174:bis-dipicolylamine-Zinc(II)