Magnesium sulfate against oxidative damage of membrane lipids: A theoretical model
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Date
2017
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Abstract
The role of magnesium sulfate as an inhibitor of lipid peroxidation has been poorly understood, although this salt has been intensively used in a wide range of diseases related to lipid peroxidation, for example, preeclampsia. Classical molecular dynamics (MD) simulations of a lipid bilayer in the presence of (OH)-O-. radicals and MgSO4 were performed to study their effects on membrane properties. Additionally, quantum chemistry (QC) calculations for MgSO4, (OH)-O-., MgSO4 (OH)-O-., [MgSO4(H2O)(4)], and [MgSO4(H2O)(4) (OH)-O-.] were performed to analyze the interactions between OH Mg. The MD results showed that the Mg salt is hydrated, forming a contact ion pair (CIP) that is adsorbed on the membrane surface close to phosphate groups. Comparisons of MD calculations for Mg-O distances indicate good agreement with theoretical QC and experimental studies. MD results also reveal that MgSO4 increases the thickness and the compressibility modulus of the membrane, indicating that it is less compressible. In contrast, DFT calculations show important OH MgASO(4) interactions in hydrated systems that inhibit the radical action by resonance in the SO4- group (smearing the spin density). These results, together with the reported experimental findings of OH high mobility in water and fast water exchange in Mg+2, may explain the MgSO4 protective effect against lipid peroxidation on cellular membranes.
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Keywords
DFT, lipid peroxidation, MgSO4, Molecular dynamics, OH radical