EFFECT OF IMIDAZOLE DERIVATIVE IONIC LIQUIDS ON LIPASE DYNAMICS AND STABILITY WITH MOLECULAR DYNAMICS SIMULATION APPROACH

• Main Author: Iin Nur Indra, Asep
• Format: Theses
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/49122
• Institution: Institut Teknologi Bandung

Lipase is a potential enzyme for various catalysis reactions. In industry, lipases are widely used for manufacturing products. Most of the production process uses organic solvents. Its application in the food and medical industries are very limited due to these solvents are volatile and have a high toxicity. Therefore, it is necessary to develop solvents that have properties similar to organic solvents. The alternative is an ionic liquid, organic ion which has a low melting point that result in liquid at room temperature. It has a high solubility in both water and organic solvents. Ionic liquids have many advantages such as non-volatile, reusable, and more environmentally friendly. In previous studies, imidazole-based ionic liquids were able to increase lipase activity by up to 28.9%. However, it is not yet known how these solvents action interacts in increasing lipase activity. This level of research can be understood up to the atomic level by molecular dynamics simulations. Molecular dynamics simulation is a method to find out the stability and dynamics of the enzymes in certain solvent systems. Furthermore, this research aims to study the effect of imidazole derivative ionic liquids on the stability and dynamics of lipase in silico method. The simulations were carried out on a lipase system in water and imidazole derivative ionic liquids. Dynamic production was carried out for 100 nanoseconds with 2 femtoseconds integration times. The software that used was GROMACS. The results obtained at 40oC have no effects. Meanwhile, the lipase system with [EMIM]Br remained stable at 100oC with an RMSD value of 2.9 Å. From the value of RMSF, it was informed that fluctuation of the lipase system with solvent [EMIM]Br was moderately low but the mobility of the residue in the lid tend to have sharp fluctuations. The lid is a part of lipase segment which has an important role on catalytic effects. In the analysis of the contact number, it is known that the solvent [EMIM]Br is closer to protein rather than the other ionic liquids. It is undeniable that [EMIM]Br can stabilize the structure of proteins by protecting lipases while maintaining the dynamics of the area covered. The results of this study have provided information on the atomic level about the stability and lipase activity in ionic liquids derived from imidazole.