Exploration of structural geometry and binding mode of a nephrotoxin molecule: Citrinin

Abstract

We have performed the structural optimization of citrinin, a fungal nephrotoxin molecules, by Gaussian 09 at B3LYP/6-311 G(d,p) base set. The structural and physicochemical parameters for optimized geometry were calculated and compared with its known crystal structure. The energies of molecular orbitals (HOMO and LUMO) were computed which confirmed the eventual charge transfer within the molecule. Further, molecular docking of citrinin with human serum albumin (HSA) confirmed the formation of five H-bonds with Tyr150, Lys199, Arg222, His242 and Arg257 of 2.97, 3.13, 3.28, 3.27, and 3.33 A bond length respectively. The HSA-citrinin complex showed the -7.8 Kcal/mol of binding energy in its lowest energy conformer. DFT computation recommend the resemblance of citrinin structure in gas and solid phases and with its X-ray diffracted one. © 2018 IEEE.