Prostate cancer cells have been reported to have both downregulated expression of the membrane proteins including zinc transporters and caveolin-1 (Cav-1) and decreased zinc ion levels relative to prostate normal cells.In our study, we found that the benzazole derivatives 5-amino-2-benzooxazol-2-yl-phenol (1 in this paper), which was reported to emit strong fluorescence in BSA resulted from an excited-state intramolecular proton transfer (ESIPT) reaction, was sensitive to protein α-helices and its intensity is positively correlated with the α-helix content in a protein.