TY - JOUR AU - Kumari, Pratibha AU - Kumari, Monika AU - Kashyap, Hemant K. TI - Counter-effects of Ethanol and Cholesterol on the Heterogeneous PSM-POPC Lipid Membrane: A Molecular Dynamics Simulation Study JF - JOURNAL OF PHYSICAL CHEMISTRY B J2 - J PHYS CHEM B VL - 123 PY - 2019 IS - 45 SP - 9616 EP - 9628 PG - 13 SN - 1520-6106 DO - 10.1021/acs.jpcb.9b07107 UR - https://m2.mtmt.hu/api/publication/31023172 ID - 31023172 N1 - Cited By :13 Export Date: 27 January 2023 CODEN: JPCBF Correspondence Address: Kashyap, H.K.; Department of Chemistry, India; email: hkashyap@chemistry.iitd.ac.in AB - In a recent work, we reported that the presence of ethanol molecules leads to significant changes on the structural stability of a homogeneous sphingomyelin bilayer. We observed that at higher concentrations of ethanol (>= 20 mol %), the structure of the PSM (N-palmitoyl-sphingomyelin) bilayer is almost lost. H-bond analysis revealed that ethanol molecules form H-bonds with the PSM lipids at the cost of PSM-PSM intermolecular H-bonding interactions, subsequently leading to destabilization of the homogeneous PSM bilayer. Biological membranes are heterogeneous and anisotropic in nature. Previously, it has been reported that partitioning of amphiphilic molecules across the lipid bilayer is governed by the lipid composition and cholesterol content. In order to further enhance our understanding towards the interaction of ethanol in the heterogeneous membrane environment, herein, we have investigated the influence of 5 and 20 mol % of ethanol on the structure and stability of two heterogeneous bilayers: a binary bilayer comprising PSM and POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) lipids and a ternary bilayer consisting of cholesterol along with PSM and POPC. The study reveals that the disordering and destabilizing effects of ethanol on the binary bilayer systems are enhanced as compared to that on the homogeneous PSM bilayer. However, the presence of cholesterol mitigates the influence of ethanol on the lipid bilayer because of its condensing and ordering effects on other lipids. LA - English DB - MTMT ER - TY - JOUR AU - Kumari, Pratibha AU - Kashyap, Hemant K. TI - DMSO induced dehydration of heterogeneous lipid bilayers and its impact on their structures JF - JOURNAL OF CHEMICAL PHYSICS J2 - J CHEM PHYS VL - 151 PY - 2019 IS - 21 PG - 12 SN - 0021-9606 DO - 10.1063/1.5127852 UR - https://m2.mtmt.hu/api/publication/31566129 ID - 31566129 AB - Recently, we have reported that higher concentrations of dimethyl sulfoxide (DMSO) exhibit an enhancement in the structural ordering of the homogeneous N-palmitoyl-sphingomyelin (PSM) bilayer, whereas the presence of DMSO at lower concentrations leads to minor destabilization of the PSM bilayer structure. In this study, we aim to understand how these two modes of action of DMSO diversify for heterogeneous bilayers by employing atomistic molecular dynamic simulations. A binary bilayer system comprising PSM and 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and a ternary bilayer system consisting of cholesterol along with PSM and POPC are the two heterogeneous biomimetic bilayers studied herein. We have simulated both the mixed lipid bilayer systems at 323 K, which is above the main phase transition temperature of the PSM lipid. This study reveals that DMSO exerts contrasting effects on the structure and stability of mixed bilayer systems, depending on its concentration. At 5 mol% of DMSO, the binary bilayer system shows slight disordering of lipid tails in conjunction with an appreciable increase in the area per lipid (APL), whereas for the ternary bilayer system, the orientational ordering of the lipid tails does not alter much; however, a slight expansion in the APL is observed. On the other hand, at 20 mol% of DMSO, an appreciable increase in the ordering of lipid tails for both the mixed bilayer systems occurs, depicting an enhancement in the structural stability of the bilayers. Furthermore, the H-bond analysis reveals that water-lipid H-bonding interaction decreases with increasing concentration of DMSO. We also observe contraction of the water-lipid interfacial region, pointing out DMSO induced dehydration at the lipid head-group region, and the dehydration effect is prominent for 20 mol% of DMSO. Furthermore, the computed free energies suggest that the free energy required for the transfer of a DMSO molecule from the lipid head-group region to the lipid head-tail interface is higher for the cholesterol containing ternary bilayer. Published under license by AIP Publishing. LA - English DB - MTMT ER - TY - JOUR AU - Eriksson, Emma S E AU - Eriksson, Leif A TI - The Influence of Cholesterol on the Properties and Permeability of Hypericin Derivatives in Lipid Membranes JF - JOURNAL OF CHEMICAL THEORY AND COMPUTATION J2 - J CHEM THEORY COMPUT VL - 7 PY - 2011 IS - 3 SP - 560 EP - 574 PG - 15 SN - 1549-9618 DO - 10.1021/ct100528u UR - https://m2.mtmt.hu/api/publication/24691244 ID - 24691244 N1 - Megjegyzés-21636440 : FN Thomson Reuters Web of Knowledge Cited By :33 Export Date: 24 September 2019 Correspondence Address: Eriksson, L. A.; School of Chemistry, National University of Ireland - Galway, Galway, Ireland; email: leif.eriksson@nuigalway.ie LA - English DB - MTMT ER -