An ESIPT fluorescent probe sensitive to protein α-helix structures

Area of Science:

• Biochemistry
• Molecular Biology
• Cancer Research

Background:

• Membrane proteins, crucial for cellular functions, exhibit altered expression in diseases like prostate cancer.
• Prostate cancer cells show reduced expression of membrane proteins, including zinc transporters, compared to normal cells.

Purpose of the Study:

• To develop a fluorescence probe capable of detecting alterations in protein alpha-helical structures.
• To differentiate between normal and cancerous prostate cells based on membrane protein characteristics.

Main Methods:

• Design and synthesis of a benzazole derivative exhibiting excited-state intramolecular proton transfer (ESIPT) fluorescence.
• Utilizing molecular docking to predict binding affinity within protein alpha-helical regions.
• Cellular localization studies and fluorescence intensity measurements in normal and cancerous prostate cells.

Main Results:

• The benzazole probe's ESIPT fluorescence intensity positively correlates with protein alpha-helix content.
• The probe binds to transmembrane alpha-helical regions of membrane proteins, localizing to cell membranes.
• Significant differences in ESIPT fluorescence intensity were observed between normal and prostate cancer cells.

Conclusions:

• The benzazole probe effectively distinguishes individual prostate cancer cells from normal cells.
• Changes in probe fluorescence reflect altered membrane protein expression, potentially aiding early prostate cancer diagnosis.