Molecular View of the Interaction of S-Methyl Methanethiosulfonate with DPPC Bilayer

VIRGINIA MIGUEL; MARÍA E DEFONSI LESTARD; MARÍA E. TUTTOLOMONDO; SONIA B. DÍAZ; AIDA BEN ALTABEF; MARCELO PUIATTI; ADRIANA B. PIERINI

ELSEVIER SCIENCE BV

Lugar: Amsterdam; Año: 2016 vol. 1858 p. 38 - 38

e present molecular dynamics (MD) simulation studies of the interaction of a chemo preventive and protective agent, S-methyl methanethiosulfonate (MMTS), with a model bilayer of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC). We analyzed and compared its diffusion mechanisms with the related molecule dimethyl sulfoxide (DMSO). We obtained spatially resolved free energy profiles of MMTS partition into a DPPC bilayer in the liquid-crystalline phase through Potential of Mean Force (PMF) calculations using an umbrella sampling technique. These profiles showed a minimum for MMTS close to the carbonyl region of DPPC. The location of MMTS molecules in the DPPC bilayer observed in the MD were confirmed by previous SERS studies.1 We decomposed PMF profiles into entropic and enthalpic contributions. These results showed that the driving force for the partitioning of MMTS into the upper region of DPPC is driven by a favorable entropy change while partitioning into the acyl chains is driven b