In Silico Evaluation of the Structural Dynamics Beta-Amylase from Sweet Potato (Ipomoea batatas)

Background: Sweet potato tubers are invaluable crop that could serve both dietary and industrial purposes owing to its high β-amylase content. β-amylases play essential role in plant carbohydrate metabolism as well as in many industrial applications such as the malting process in the brewing and distilling industries.

Aim: This study aims at better understanding of the evolutionary and molecular properties, and structural dynamics of β-amylase of sweet potato using in silico approach.

Methodology: 16 of the 250 sequences that are at least 69% identity to the query sequence (P10537) were manually selected from UniProt database for further analysis.

Result: It has theoretical isoelectric point of 4.97 and molecular weight of 56 kDa. The root-mean-square fluctuation (RMSF) of sweet potato β-amylase showed possible conservation of the amino acid residues 105-130 and 260-345, with highest fluctuation in C-terminal loop (residues 443-498). The catalytic role of Glu187 and Thr344 in β-amylase of sweet potato has been elucidated, and it provided the missing link in the previously available mechanisms, while Cys96 is essential for the inactivation of enzyme activity.

Conclusion: Elucidation of molecular mechanisms of expression and catalytic activity, together with the understanding of physicochemical properties of β-amylase from sweet potato will help in development of useful applications that are of industrial importance.