A highly selective fluorescent ESIPT probe for the dual specificity phosphatase MKP-6

Area of Science:

• Biochemistry
• Chemical Biology
• Molecular Probes

Background:

• Protein tyrosine phosphatases (PTPs) are crucial enzymes involved in cellular signaling.
• Dysregulation of PTP activity is linked to various diseases, including cancer and metabolic disorders.
• Development of selective and sensitive probes for PTPs is essential for biological research and diagnostics.

Purpose of the Study:

• To design and synthesize a highly selective fluorescent probe for protein tyrosine phosphatase (PTP) activity.
• To investigate the mechanism of fluorescence signal generation upon PTP-mediated hydrolysis.
• To demonstrate the utility of the probe for detecting PTP activity in biological systems.

Main Methods:

• A novel fluorescent probe was synthesized by phosphorylating the 2-(2'-hydroxyphenyl)benzothiazole (HBT) chromophore.
• The probe's response to PTP enzymatic activity was evaluated using biochemical assays.
• Fluorescence spectroscopy was employed to analyze the probe's spectral properties, including the Stokes shift.

Main Results:

• The designed probe exhibited high selectivity for PTPs.
• Enzymatic hydrolysis of the phosphorylated probe triggered an excited-state intramolecular proton transfer (ESIPT) process.
• This ESIPT mechanism resulted in a significantly large Stokes shift, enabling sensitive fluorescence detection.

Conclusions:

• A novel, highly selective fluorescent probe for PTPs was successfully developed.
• The probe's mechanism relies on PTP-mediated hydrolysis and ESIPT, leading to a large Stokes shift.
• This probe represents a valuable tool for studying PTP function and for potential diagnostic applications.