Immobilization of pectinase on chitosan-alginate-clay composite beads: Experimental, DFT and molecular docking studies

Pectinase was immobilized on chitosan-alginate-clay (CAC) beads using epichlorohydrin (ECH) as the crosslinker. Prepared beads and immobilization product were analyzed by Fourier Transform Infrared Spectrophotometry (FTIR) and Scanning Electron Microscopy (SEM). Experimental data covered some hydrolytic properties of the immobilized enzyme, such as pH, temperature, reusability, concentration, and storage time. The immobilization procedure increased the optimal temperature to 60 ◦C and maximum activity was obtained at pH (6.0). After 5 cycles of reuse, approximately 45% of the initial activity of the immobilized enzyme remained. Free pectinase, CAC, and immobilization product were also investigated by Gaussian calculations, the HF/6-31g basis set. Furthermore, Aspergillus niger proteins (PDB ID: 3K4P and 7BLY) and Staphylococcus aureus (PDB ID: 1JIJ) were examined for molecular docking calculations, and ADME/T calculations were made to examine the effects and reactions of these molecules in human metabolism.