Molecular Characterization of Alpha-Amylase of Aspergillus flavus and Aspergillus oryzae: An In Silico Study

Alpha amylases (EC 3.2.1.1.) hydrolyze polysaccharides like starch and glycogen to create oligosaccharides of different sizes by random cleavage of internal 1, 4-glucosidic linkages. These enzymes are produced by many different bacteria and fungi. In this investigation, α-amylase from Aspergillus flavus and Aspergillus oryzae was taken into consideration. Amino acid sequences and protein structure were retrieved from databases. Sequences of Aspergillus oryzae possess a high number of charged residues whereas Aspergillus flavus have a higher abundance of uncharged polar and hydrophobic amino acid residues. 3 common superfamilies were observed between both species. The alignment of sequences showed their similar conservative nature. Non-covalent intra-protein interactions like the salt bridge, aromatic-aromatic interactions, aromatic-sulfur interactions and cation-pi interactions helped to increase the stability of α-amylase of Aspergillus oryzae. The tunnels and cavities also help to increase the functionality and catalytic activity of α-amylase. This study will also be helpful for protein engineering.