Spectroscopic and molecular modcking analysis of the interaction between Trypsin and Cefpirome

The interaction between Cefpirome and Trypsin was studied using multi-spectroscopy and molecular docking methods. The results showed that quenching mechanism of the Trypsin-Cefpirome system was probably static. The main interaction force was electrostatic force, and the number of binding sites in this system was approximately equal to 1. The quenching curves indicated that the tyrosine and tryptophan residues were both involved in the reaction. Synchronous fluorescence spectroscopy further confirmed that the main binding site was closer to tryptophan residues. The distance (r) between Trypsin and Cefpirome was less than 7 nm, which indicated that the energy transfer from Trypsin to Cefpirome was non-radiative energy transfer. The values of the Hill’s coefficients showed that there was negative cooperativity in the interaction between Cefpirome and Trypsin.