All-atom Molecular Dynamics model for mycobacterial plasma membrane

Abstract

Phosphatidyl-myo-inositol mannosides (PIMs) are an essential component of the cell envelope and the most predominant at the inner membrane (IM) of M. tuberculosis. In this work, we propose an Molecular Dynamics (MD) M. tuberculosis IM model composed of PIM2 lipids. The study was divided in three parts: influence of the temperature in the PIM2 membrane stability, self-assembly abilities of the PIM2 lipid and the behavior when a trans membrane protein is inserted in PIM2 membrane. Our results show that the model is able to reproduce the gel phase observed at 310 K and the transition to a fluid phase at 328.15 K. Also, the spontaneous self-assembly of randomly distributed lipids in a vesicular aggregate was observed. Finally, we observe that the PIM2 membrane is more stable than DPPC membranes when a Tap protein is inserted. Once Tap eflux pump is related to multidrug resistance of M. tuberculosis, this result indicated that the use of the proper lipid model is essential to the proper depiction and modeling of these systems. Graphical TOC Entry