A mutant T1 lipase homology modeling, and its molecular docking and molecular dynamics simulation with fatty acids

A thermostable T1 lipase from Geobacillus zalihae exhibits broad substrate specificity and good potential application in fats and oils. However, structural insight into the enzyme against substrates is poorly understood at the molecular level. Herein, the study aimed to examine interactions between a mutant T1 lipase (Mut-T1 lipase) and selected fatty acids (caprylic, myristic, stearic, oleic, linoleic and linolenic acids) by performing molecular docking and molecular dynamics (MD) simulation. The structure of Mut-T1 lipase obtained by homology modeling was reliable for molecular docking and MD simulation. Molecular docking revealed that Mut-T1 lipase showed low binding affinity for caprylic acid (-4.97 kcal/mol) compared to the other fatty acids (-5.65 to -6.88 kcal/mol). However, the conformation of Mut-T1 lipase-caprylic acid complex was comparably stable during the simulation, in terms of less root-mean square fluctuation. Besides, solvent accessible surface area value of Mut-T1 lipase-fatty acid complexes decreased with increasing chain length of fatty acid. van der Waals interactions were requisite in maintaining complex stability during the binding process. This work provides structural insight into interactions between the lipase and the fatty acids, which will facilitate design and applications of new mutants of T1 lipase in modifying fats and oils.