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Azide-Masked Fluorescence Turn-On Probe for Imaging Mycobacteria.
Liyanage, Sajani H; Raviranga, N G Hasitha; Ryan, Julia G; Shell, Scarlet S; Ramström, Olof; Kalscheuer, Rainer; Yan, Mingdi.
Afiliação
  • Liyanage SH; Department of Chemistry, University of Massachusetts, Lowell, Massachusetts 01854, United States.
  • Raviranga NGH; Department of Chemistry, University of Massachusetts, Lowell, Massachusetts 01854, United States.
  • Ryan JG; Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States.
  • Shell SS; Department of Biology and Biotechnology, Worcester Polytechnic Institute, Worcester, Massachusetts 01609, United States.
  • Ramström O; Department of Chemistry, University of Massachusetts, Lowell, Massachusetts 01854, United States.
  • Kalscheuer R; Department of Chemistry and Biomedical Sciences, Linnaeus University, SE-39182 Kalmar, Sweden.
  • Yan M; Institute of Pharmaceutical Biology and Biotechnology, Heinrich Heine University, Universitaetsstrasse 1, 40225 Duesseldorf, Germany.
JACS Au ; 3(4): 1017-1028, 2023 Apr 24.
Article em En | MEDLINE | ID: mdl-37124305
ABSTRACT
A fluorescence turn-on probe, an azide-masked and trehalose-derivatized carbazole (Tre-Cz), was developed to image mycobacteria. The fluorescence turn-on is achieved by photoactivation of the azide, which generates a fluorescent product through an efficient intramolecular C-H insertion reaction. The probe is highly specific for mycobacteria and could image mycobacteria in the presence of other Gram-positive and Gram-negative bacteria. Both the photoactivation and detection can be accomplished using a handheld UV lamp, giving a limit of detection of 103 CFU/mL, which can be visualized by the naked eye. The probe was also able to image mycobacteria spiked in sputum samples, although the detection sensitivity was lower. Studies using heat-killed, stationary-phase, and isoniazid-treated mycobacteria showed that metabolically active bacteria are required for the uptake of Tre-Cz. The uptake decreased in the presence of trehalose in a concentration-dependent manner, indicating that Tre-Cz hijacked the trehalose uptake pathway. Mechanistic studies demonstrated that the trehalose transporter LpqY-SugABC was the primary pathway for the uptake of Tre-Cz. The uptake decreased in the LpqY-SugABC deletion mutants ΔlpqY, ΔsugA, ΔsugB, and ΔsugC and fully recovered in the complemented strain of ΔsugC. For the mycolyl transferase antigen 85 complex (Ag85), however, only a slight reduction of uptake was observed in the Ag85 deletion mutant ΔAg85C, and no incorporation of Tre-Cz into the outer membrane was observed. The unique intracellular incorporation mechanism of Tre-Cz through the LpqY-SugABC transporter, which differs from other trehalose-based fluorescence probes, unlocks potential opportunities to bring molecular cargoes to mycobacteria for both fundamental studies and theranostic applications.

Texto completo: 1 Base de dados: MEDLINE Idioma: En Ano de publicação: 2023 Tipo de documento: Article

Texto completo: 1 Base de dados: MEDLINE Idioma: En Ano de publicação: 2023 Tipo de documento: Article