Probing the interaction of cefodizime with human serum albumin using multi-spectroscopic and molecular docking techniques

Abstract

To know the interaction of cefodizime (CEF) with human serum albumin (HSA), techniques of different spectroscopies and molecular modeling were used. The inner filter effects were eliminated to get accurate binding parameters. Steady state fluorescence suggested a static type for CEF–HSA interaction, and the complex formation had a high affinity of 105Lmol−1. On the basis of the thermodynamic results and site marker competitive experiments, it was considered that CEF was bound to site I (subdomain IIA) of HSA mainly by hydrogen bonds and van der Waals force. The calculated binding distance (r) indicated that the non-radioactive energy transfer came into being in the interaction between CEF and HSA. Furthermore, molecular modeling was applied to further define that CEF interacted with the Trp214, Lys199, Phe211, Leu238 residues of HSA. In addition, three-dimensional fluorescence and circular dichroism (CD) results showed that the binding of CEF can cause conformational and some microenvironmental changes of HSA. This paper provides reasonable models helping us further understand the transportation and distribution of CEF when it spreads into human blood serum which is of great importance in pharmacology and pharmacodynamics.