Local entropy difference upon a substrate binding of a psychrophilic α-amylase and a mesophilic homologue

► MD simulations of psychrophilic and mesophilic α-amylases were carried out. ► We calculated protein conformational entropy changes upon substrate bindings. ► The entropy changes were decomposed into contributions of individual amino acids. ► Differences of entropy changes are found to be attributed to the insertion residues. ► Difference in the entropy change well explains the temperature dependences.