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

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

BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES

ELSEVIER SCIENCE BV

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

0005-2736

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 of1,2-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 was 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