Spectroscopic study on the interaction of Trypsin with Bicyclol and analogs

The interactions between Trypsin and Bicyclol or analogs (Bifendate, I, II and III) were investigated by spectrophotometric methods. It was found that Bicyclol or analogs had strong ability to quench the intrinsic fluorescence of Trypsin by a static quenching procedure. The binding constants were obtained at three temperatures. The thermodynamics parameters reveal that the hydrophobic and electrostatic interactions play an important role in the interaction. Results showed that the microenvironments of tryptophan residue of Trypsin were disturbed by the analogs. Results indicated that Bifendate was the strongest quencher among five compounds. (C) 2013 Elsevier B.V. All rights reserved.