Binding of rare earth metal complexes with an ofloxacin derivative to bovine serum albumin and its effect on the conformation of protein

► The crystal structures of two water-soluble Pr (III) and Nd (III) complexes with an ofloxacin derivative were obtained. ► The complexes could bind to bovine serum albumin. ► Circular dichroism, together with methods (SELCON3, CONTIN, CDSSTR) was used to estimate protein secondary structures.