Docking of Polyaniline with D-Amino Acid Oxidase of Rhodosporidium toruloides and Pig Kidney-An Insight into the Mechanism of Binding for Immobilization in Polyaniline Supports

Abstract

The interaction of Polyaniline (PAni) with Rhodosporidium toruloides D-amino acid oxidase (RtDaao) and pig kidney D-aao (PkDaao) was studied by bioinformatics approach. The interaction of PAni with RtDaao does not interfere with the substrate binding and hence the D-amino acid oxidase (D-aao) activity is unaffected by the ligand. The active site cavity of pig kidney D-aao (PkDaao) is comprised of the residues Leu 51, Tyr 224, Tyr 228, Arg 283 and Gly 313. PAni interacts with Leu 51 and Thr 317 of chain G of the PkDaao with interaction energy of -2.5 and -1.09 kcal/mol respectively. D-aao was immobilized onto PAni-sodium alginate beads using glutaraldehyde as the crosslinking agent. 1g of the PAni-sodium alginate D-aao beads contained 0.093 ml or 0.385 U of the D-aao enzyme. The Activity Yield (AY) was calculated as 18.92% as determined by the pyruvate method of detection while, the AY was calculated as 17.3% as determined by the o-PDA method of D-aao assay of the beads. The PAni-sodium alginate D-aao beads were characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Energy Dispersive X-ray Diffraction (EDX), Thermogravimetric Analysis (TGA) and Scanning Electron Microscopic analysis.