Real-Time Visualization of Cysteine Metabolism in Living Cells with Ratiometric Fluorescence Probes

Abstract

Sulfite from cysteine metabolism in living cells plays a crucial role in improving the water solubility of metabolic xenobiotics for their easier excretion in urine or bile. However, an imbalance of sulfite in vivo would lead to oxidative stress or age-related diseases, and an effective strategy for real-time imaging of cysteine metabolism in living cells is still lacking due to its low metabolite concentration and rapid reaction kinetics. Herein, a cyanine moiety based ratiometric fluorescence probe was developed for highly selective and sensitive detection of sulfite in aqueous solution and living cells. The free probe exhibited an orange emission color, and the fluorescence color would gradually change to blue once sulfite anions selectively reacted with the unsaturated carbon double bonds in the probe molecule. This ratiometric fluorescence manner endowed the probe excellent sensitivity with a detection limit of 0.78 nM, which was then explored to image the kinetic process of sulfite release in hepatic BRL cells after incubating with an excess amount of cysteine. This strategy opens new opportunities for revealing thiol-containing species metabolism and even quantitatively tracking their distributions in live cells or organelles.

The chronological evolution of small organic molecular fluorescent probes for thiols

“…101 Subsequently, several examples have been reported to describe the dynamic thiol metabolism processes utilizing observable uorescent methodology (23)(24)(25)(26). [102][103][104][105][106] Further, the simultaneous detection of thiols and reactive oxygen species or reactive nitrogen species have also been reported in recent years to evaluate the cellular crosstalk of these redox regulating species. 38 Among the currently reported thiol uorescent probes, design strategies for the specic detection of Cys or GSH have been well studied.…”

A New Strategy: Distinguishable Multi-substance Detection, Multiple Pathway Tracing Based on a New Site Constructed by the Reaction Process and Its Tumor Targeting

“…Metabolism is the general term for a series of ordered chemical reactions that take place in the body to sustain life. Metabolism is also called cellular metabolism. , Chemical reactions in metabolism can be summarized as “metabolic pathways”, which convert one chemical substance to another through a series of enzymatic reactions. The signaling pathway refers to a series of enzymatic reaction pathways that can transmit the extracellular molecular signals through the cell membrane into the cell to exert effects, and metabolism is one of the signaling pathways.…”

An Integrated LC-MS/MS Strategy for Quantifying the Oxidative-Redox Metabolome in Multiple Biological Samples

“…But this was a semiquantification method (or pseudo untargeted metabolomics) without absolute quantification by using standards and the instrument parameters were not individually optimized. To fit the urgent demand from biological issues for the precise quantification of specific metabolites, metabolomics is gradually refined and increasing methods on targeted metabolomics are reported. − Our work established a new concept of “oxidative-redox metabolome”, using metabolomic perspective to evaluate cellular oxidative-redox state. This strategy can also be derived to other biological functional metabolome.…”