Lid dynamics of porcine pancreatic lipase in non-aqueous solvents

• Published in: Biochimica et biophysica acta Vol. 1860; no. 10; pp. 2326 - 2334
• Main Authors: Haque, Neshatul, Prabhu, N. Prakash
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.10.2016
• Subjects: Amino Acid Sequence; Animals; Binding Sites; Colipases - chemistry; Colipases - genetics; Colipases - metabolism; energy; ethanol; Ethanol - chemistry; Hydrolysis; industrial applications; Lid opening; Lipase - chemistry; Lipase - genetics; Lipase - metabolism; Molecular Dynamics Simulation; Molecular simulation; mutants; Octanol; Octanols - chemistry; Pancreas - chemistry; Pancreas - enzymology; Pancreatic lipase; Protein Conformation; solvents; Substrate Specificity; surface area; swine; Swine - genetics; temperature; toluene; Toluene - chemistry; triacylglycerol lipase; Water; Molecular simulation; Water; PPL-O; Pancreatic lipase; PPL-Cl; Lid opening; Octanol; RMSF; PPL+colip; RMSD; PPL-colip; PCA; Rg; PPLmut-Cl; RMSIP; SASA
• ISSN: 0304-4165; 0006-3002; 1872-8006
• DOI: 10.1016/j.bbagen.2016.05.006

Understanding the dynamics of enzymes in organic solvents has wider implications on their industrial applications. Pancreatic lipases, which show activity in their lid open-state, demonstrate enhanced activity in organic solvents at higher temperatures. However, the lid dynamics of pancreatic lipases in non-aqueous environment is yet to be clearly understood. Dynamics of porcine pancreatic lipase (PPL) in open and closed conformations was followed in ethanol, toluene, and octanol using molecular simulation methods. In silico double mutant D250V and E254L of PPL (PPLmut-Cl) was created and its lid opening dynamics in water and in octanol was analyzed. PPL showed increase in solvent accessible surface area and decrease in packing density as the polarity of the surrounded solvent decreased. Breaking the interactions between D250-Y115, and D250-E254 in PPLmut-Cl directed the lid to attain open-state conformation. Major energy barriers during the lid movement in water and in octanol were identified. Also, the trajectories of lid movement were found to be different in these solvents. Only the double mutant at higher temperature showed lid opening movement suggesting the essential role of the three residues in holding the lid in closed conformation. The lid opening dynamics was faster in octanol than water suggesting that non-polar solvents favor open conformation of the lid. This study identifies important interactions between the lid and the residues in domain 1 which possibly keeps the lid in closed conformation. Also, it explains the rearrangements of residue–residue interactions during lid opening movement in water and in octanol. •Dynamics of pancreatic lipase in non-aqueous solvents was studied by MD simulation.•Lid opening was observed for double mutant at 400K in water and in octanol.•Lid trajectory and energy barriers were identified from free energy surface.•Water and octanol follow different lid opening pathways.