Computational Model of the Effect of a Surface-Binding Site on the Saccharomycopsis fibuligera R64 α-Amylase to the Substrate Adsorption

α-Amylase is one of the important enzymes in the starch-processing industry. However, starch processing requires high temperature, thus resulting in high cost. The high adsorptivity of α-amylase to the substrate allows this enzyme to digest the starch at a lower temperature. α-Amylase from Saccharomycopsis fibuligera R64 (Sfamy R64), a locally sourced enzyme from Indonesia, has a high amylolytic activity but low starch adsorptivity. The objective of this study was to design a computational model of Sfamy R64 with increased starch adsorptivity using bioinformatics method. The model structure of Sfamy R64 was compared with the positive control, ie, Aspergillus niger α-amylase. The structural comparison showed that Sfamy R64 lacks the surface-binding site (SBS). An SBS was introduced to the structure of Sfamy R64 by S383Y/S386W mutations. The dynamics and binding affinity of the SBS of mutant to the substrate were also improved and comparable with that of the positive control.