The fluorescence spectroscopic study on the interaction between imidazo[2,1-b]thiazole analogues and bovine serum albumin

The interaction between imidazo[2,1-b]thiazole (IMTZ) and bovine serum albumin (BSA) was analyzed by fluorescence and ultraviolet spectroscopy at 302 and 310 K under simulative physiological conditions. The results show that IMTZ can effectively quench the intrinsic fluorescence of BSA via static and dynamic quenching. The binding constant, binding sites of IMTZ with BSA were calculated. According to the Förster non-radiation energy transfer theory, the average binding distance between IMTZ and BSA was obtained. What's more, the synchronous fluorescence spectra indicated that the conformation of BSA has been changed. The results provided the information for the binding of IMTZ to BSA, and the influences of substituent group on the interaction were also discussed.

Graphical abstractThe interaction between imidazo[2,1-b]thiazole (IMTZ) analogues and bovine serum albumin (BSA) was studied by fluorescence and UV–Vis spectroscopy. The quenching mechanism, binding constants and binding distance were obtained. The comparison of binding potency of IMTZ and BSA suggested that the substituent on the benzene ring enhance the binding affinity of IMTZ and BSA.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► We explored the interaction of BSA and IMTZ by spectroscopic methods. ► The fluorescence quenching mechanism is static and dynamic quenching. ► The binding constants and binding sites were calculated. ► The synchronous fluorescence spectra indicated that the conformation of BSA has been changed. ► The substituent on the benzene ring enhance the binding affinity of IMTZ and BSA.