Cysteamine-Based Cell-Permeable Zn²⁺-Specific Molecular Bioimaging Materials: From Animal to Plant Cells

Abstract

Structure-interaction/fluorescence relationship studies led to the development of a small chemical library of Zn(2+)-specific cysteamine-based molecular probes. The probe L5 with higher excitation/emission wavelengths, which absorbs in the visible region and emits in the green, was chosen as a model imaging material for biological studies. After successful imaging of intracellular zinc in four different kinds of cells including living organisms, plant, and animal cells, in vivo imaging potential of L5 was evaluated using plant systems. In vivo imaging of translocation of zinc through the stem of a small herb with a transparent stem, Peperomia pellucida, confirmed the stability of L5 inside biological systems and the suitability of L5 for real-time analysis. Similarly, fluorescence imaging of zinc in gram sprouts revealed the efficacy of the probe in the detection and localization of zinc in cereal crops. This imaging technique will help in knowing the efficiency of various techniques used for zinc enrichment of cereal crops. Computational analyses were carried out to better understand the structure, the formation of probe-Zn(2+) complexes, and the emission properties of these complexes.

Purine‐Based Fluorescent Sensors for Imaging Zinc Ions in HeLa Cells

“…So there is redshift of 49 nm in the absorption spectrum, while for the emission spectrum, it is 17 nm. With other metal ions, such as Na + , K + , Mn 2+ , Fe 3+ , Co 2+ , Ni 2+ , Cu 2+ , Ag + , Cd 2+ , and Hg 2+ , there is no significant enhancement in the emission intensity (Figure ), and so, the observed enhancement in fluorescence could be due to photoinduced‐electron‐transfer (PET) quenching between the chelating unit and the fluorophore , , . As the concentration of zinc ions is increased, there is enhancement in the fluorescence of HL1 , as can be seen in Figures and S8; this could be due to an equilibrium between the free and bound zinc ions with the ligand.…”

“…But HL1 and HL3 exhibit larger enhancement with Zn 2+ ions. Schiff bases have been used as fluorescent sensors for selectively detecting different metal ions (Figure ) . In a previous article, we showed the crystallographic signatures of an adenine‐based dipolar imine‐phenol Schiff base with different metal ions.…”

A conveniently prepared and hypersensitized small molecular fluorescent probe: Rapidly detecting free zinc ion in HepG2 cells and Arabidopsis

“…Meanwhile, zinc ions act a significant role in many biochemical reactions in plants such as maize, sorghum and sugarcane, which show reduced photosynthetic carbon metabolism due to zinc deficiency (Dittmer, etal., 2009;Sinha, etal., 2013;Chyan, etal., 2014) [7][8][9]. Therefore, it is of great significance to develop analytical methods for detecting and monitoring Zn 2+ at the level of cells and tissues in the body including plants and animals.…”

Highly selective fluorescence imaging of zinc distribution in HeLa cells and Arabidopsis using a naphthalene-based fluorescent probe

“…3,4 Furthermore, zinc plays an important role in many biochemical reactions within plants. [5][6][7][8][9][10][11][12] Plants such as maize, sorghum and sugarcane show reduced photosynthetic carbon metabolism due to zinc deficiency. Zinc modifies and/or regulates the activity of carbonic anhydrase, an enzyme that regulates the conversion of carbon dioxide to reactive bicarbonate species for fixation as carbohydrates in these plants.…”