title: Poly(arginine)-selective coprecipitation properties of self-assembling apoferritin and Its Tb(3+) complex: a new luminescent biotool for sensing of poly(arginine) and its protein conjugates.
abstract: The apoferritin protein and apoferritin-Tb(3+) complex were demonstrated to form oligomeric and polymeric self-assemblies in neutral aqueous solutions, based on characterization by using luminescence and UV/Vis spectroscopy, dynamic light scattering, and transmission electron microscopy. Addition of a 20-mer or higher poly(arginine) to the solution resulted in coprecipitation through nanoscale interactions, while biological proteins and other poly(amino acids) rarely yielded precipitates under the conditions employed. The apoferritin-Tb(3+) complex assembly exhibited a particularly long-lived green luminescence in aqueous solution, and its poly(arginine)-selective precipitation behavior was followed by monitoring the changes in luminescence. The poly(arginine)-tagged albumin precipitated selectively and quantitatively, so that the apoferritin-Tb(3+) complex can function as a new luminescent biotool for the sensing of poly(arginine) and its protein conjugates.
authors.affiliation: Department of Chemistry, Graduate School of Science, Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka 558-8585, Japan. tsukube@sci.osaka-cu.ac.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tsukube
authors.forename: Yuki
authors.initials: Y
authors.lastname: Noda
authors.forename: Satoshi
authors.initials: S
authors.lastname: Shinoda
mesh_terms: D001052:Apoferritins / Q000737:chemistry*; D001120:Arginine / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D049449:Luminescence; D008667:Metalloproteins / Q000737:chemistry*; D015394:Molecular Structure; D010455:Peptides / Q000737:chemistry*; D011506:Proteins / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet; D013725:Terbium / Q000737:chemistry*; D014867:Water / Q000737:chemistry
chemical_list: D005456:Fluorescent Dyes; D028581:Lanthanoid Series Elements; D008667:Metalloproteins; D010455:Peptides; D011506:Proteins; D012996:Solutions; D014867:Water; D013725:Terbium; D001052:Apoferritins; D001120:Arginine