title: A novel near-infrared fluorescent probe for sensitive detection of β-galactosidase in living cells.
abstract: A novel near-infrared fluorescent probe for β-galactosidase has been developed based on a hemicyanine skeleton, which is conjugated with a d-galactose residue via a glycosidic bond. The probe serves as a substrate of β-galactosidase and displays rapid and sensitive turn-on fluorescent responses to β-galactosidase in aqueous solution. A 12.8-fold enhancement of fluorescence intensity at 703 nm was observed after incubation of 10 nM of β-galactosidase with 5 μM probe for 10 min. The probe can sensitively detect as little as 0.1 nM of β-galactosidase and shows linear responses to the enzyme concentration below 1.4 nM. The kinetic study showed that the probe has high binding affinity to β-galactosidase with Km= 3.6 μM. The probe was used to detect β-galactosidase in living cells by employing the premature cell senescence model. The probe exhibited strong fluorescent signals in senescent cells but not in normal cells, which demonstrates that the probe is able to detect the endogenous senescence-associated β-galactosidase in living cells.
authors.affiliation: Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
authors.forename: Jingtuo
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
authors.forename: Cong
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
authors.forename: Colina
authors.initials: C
authors.lastname: Dutta
authors.affiliation: Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
authors.forename: Mingxi
authors.initials: M
authors.lastname: Fang
authors.affiliation: Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA.
authors.forename: Shuwei
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA. Electronic address: tiwari@mtu.edu.
authors.forename: Ashutosh
authors.initials: A
authors.lastname: Tiwari
authors.affiliation: Department of Biological Sciences, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA. Electronic address: twerner@mtu.edu.
authors.forename: Thomas
authors.initials: T
authors.lastname: Werner
authors.affiliation: Institute of Chemistry, Academia Sinica, Taipei, 11529, Taiwan, Republic of China. Electronic address: luoft@gate.sinica.edu.tw.
authors.forename: Fen-Tair
authors.initials: FT
authors.lastname: Luo
authors.affiliation: Department of Chemistry, Michigan Technological University, 1400 Townsend Drive, Houghton, MI 49931, USA. Electronic address: hyliu@mtu.edu.
authors.forename: Haiying
authors.initials: H
authors.lastname: Liu
mesh_terms: D002478:Cells, Cultured; D005347:Fibroblasts; D005456:Fluorescent Dyes; D006801:Humans; D019265:Spectroscopy, Near-Infrared; D001616:beta-Galactosidase / Q000032:analysis*
chemical_list: D005456:Fluorescent Dyes; D001616:beta-Galactosidase
keywords: Fluorescence imaging; Fluorescent probe; Live cells; Near-infrared emission; β-Galactosidase