Multispectroscopic, electrochemical and molecular docking approaches on binding comparison of camptothecin, 10-hydroxycamptothecin to bovine serum albumin

Abstract Camptothecin (CPT) and 10-hydroxycamptothecin (HCPT) are two anti-tumor agents that cause the tumor cell death by inhibiting the degradation of the cleaved DNA strand. In the current study, we researched the interactions of CPT/HCPT and bovine serum albumin (BSA) with the multi-spectroscopy method, electrochemical method and molecular docking method. The inverse ratio of Ksv and Ka to temperature and the difference in UV–vis absorption indicated that there was a formed complex in both CPT-BSA system and HCPT-BSA system when they titrated into BSA solution, cyclic voltammetry and AC impedance experiments confirmed this phenomenon. The thermodynamic data demonstrated that hydrogen bonding as well as electrostatic interactions might be the leading force when they bound to BSA. The experiments of site competition and molecular docking showed that both CPT and HCPT bind to BSA on site I. Furthermore, the three-dimensional fluorescence, synchronous fluorescence and circular dichroism spectroscopy demonstrated that presence of CPT/HCPT changed the conformation of BSA.