title: Single molecular multianalyte (Ca2+, Mg2+) fluorescent probe and applications to bioimaging.
abstract: Intracellular signal transduction relies on spatial and temporal signal transmitter dynamics. To clarify the correlations of these transmitter molecules, multicolor-imaging has been widely used. However, in the case of applying multiple indicators in a cell, spectral overlap of the indicators prevents accurate quantitative analysis. Moreover, the invasive (toxic) effect, the localization, the metabolism, as well as photobleaching of these indicators complicate the situation. Here, we show that single-molecular multifluorescent probes can overcome these problems. While intracellular calcium plays a critical role as a signal transmitter and magnesium acts as a cofactor in many situations, the correlations between the two cations are now the main issue. We designed and synthesized a Ca2+-Mg2+ responsive multifluorescent probe, KCM-1. KCM-1 shows a spectral blue shift upon complexation to Ca2+ and a red shift to the presence of Mg2+. With data analyzed at different excitation wavelengths, the concentrations of Ca2+ and Mg2+ are simultaneously quantified. Furthermore, by using the AM-ester method, intracellular Ca2+ and Mg2+ concentrations are simultaneously imaged. Such a type of intracellular multiple analyte imaging by a single-molecular multifluorescent probe is successfully demonstrated for the first time.
authors.affiliation: Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama, Kanagawa 223-8522, Japan.
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Komatsu
authors.forename: Takahiro
authors.initials: T
authors.lastname: Miki
authors.forename: Daniel
authors.initials: D
authors.lastname: Citterio
authors.forename: Takeshi
authors.initials: T
authors.lastname: Kubota
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Shindo
authors.forename: Yoshiichiro
authors.initials: Y
authors.lastname: Kitamura
authors.forename: Kotaro
authors.initials: K
authors.lastname: Oka
authors.forename: Koji
authors.initials: K
authors.lastname: Suzuki
mesh_terms: D002118:Calcium / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D008274:Magnesium; D002118:Calcium