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Maleš P, Pem B, Petrov D, Jurašin DD, Bakarić D. Deciphering the origin of the melting profile of unilamellar phosphatidylcholine liposomes by measuring the turbidity of its suspensions. SOFT MATTER 2022; 18:6703-6715. [PMID: 36017811 DOI: 10.1039/d2sm00878e] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
The elucidation of the thermal properties of phosphatidylcholine liposomes is often based on the analysis of the thermal capacity profiles of multilamellar liposomes (MLV), which may qualitatively disagree with those of unilamellar liposomes (LUV). Experiments and interpretation of LUV liposomes is further complicated by aggregation and lamellarization of lipid bilayers in a short time period, which makes it almost impossible to distinguish the signatures of the two types of bilayers. To characterize independently MLV and LUV of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), the latter were prepared with the addition of small amounts of 1,2-dipalmitoyl-sn-glycero-3-phosphatidylglycerol (DPPG) which, due to the sterical hindrance and negative charge at a given pH value, cause LUV repellence and contribute to their stability. Differential scanning calorimetry curves and temperature-dependent UV/Vis spectra of the prepared MLV and LUV were measured. Multivariate analysis of spectrophotometric data determined the phase transition temperatures (pretransition at Tp and the main phase transition at Tm), and based on the changes in turbidities, the thickness of the lipid bilayer in LUV was determined. The obtained data suggested that the curvature change is a key distinguishing factor in MLV and LUV heat capacity profiles. By combining the experimental results and those obtained by MD simulations, the interfacial water layer was characterized and its contribution to the thermal properties of LUV was discussed.
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Affiliation(s)
- Petra Maleš
- Division for Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia.
| | - Barbara Pem
- Division for Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia.
| | - Dražen Petrov
- Institute of Molecular Modeling and Simulation, University of Natural Resources and Life Sciences, 1180 Vienna, Austria
| | - Darija Domazet Jurašin
- Division for Physical Chemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia
| | - Danijela Bakarić
- Division for Organic Chemistry and Biochemistry, Ruđer Bošković Institute, Bijenička 54, 10000 Zagreb, Croatia.
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Seper BC, Ko A, Abma AF, Folkerts AD, Tristram-Nagle S, Harper PE. Methylene volumes in monoglyceride bilayers are larger than in liquid alkanes. Chem Phys Lipids 2019; 226:104833. [PMID: 31738879 DOI: 10.1016/j.chemphyslip.2019.104833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 09/26/2019] [Accepted: 10/09/2019] [Indexed: 11/26/2022]
Abstract
The densities as a function of temperature of four fully hydrated saturated monoglycerides with even chain lengths ranging from eight to fourteen were determined by vibrating tube densitometry and their phase transition temperatures were determined by differential scanning calorimetry (DSC). We find the volume of a methylene group in a monoglyceride bilayer is 2% larger than in liquid alkanes at physiological temperatures, similar to the methylene group volumes found in phosphatidylcholine (PC) bilayers. Additionally, we carefully consider the traditional method of calculating component volumes from experimental data and note potential difficulties in this approach. In the literature, the ratio of terminal methyl volume (CH3) to methylene (CH2) volumes is typically assumed to be 2. By analysis of literature alkane data, we find this ratio actually ranges from 1.9 to 2.3 for temperatures ranging from 0 °C to 100 °C. For a rough sense of scale, we note that to effect a 2% reduction in volume requires of order 200 atmospheres of pressure, and pressures of this magnitude are biologically relevant. For instance, this amount of pressure is sufficient to reverse the effect of anesthesia. The component volumes obtained are an important parameter used for determining the structure of lipid bilayers and for molecular dynamics simulations.
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Affiliation(s)
- Brian C Seper
- Department of Physics and Astronomy, Calvin University, Grand Rapids, MI 49546, USA
| | - Anthony Ko
- Biological Physics Group, Physics Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
| | - Aaron F Abma
- Department of Physics and Astronomy, Calvin University, Grand Rapids, MI 49546, USA
| | - Andrew D Folkerts
- Department of Physics and Astronomy, Calvin University, Grand Rapids, MI 49546, USA
| | - Stephanie Tristram-Nagle
- Biological Physics Group, Physics Department, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, PA 15213, USA
| | - Paul E Harper
- Department of Physics and Astronomy, Calvin University, Grand Rapids, MI 49546, USA.
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Ramos MC, Horta VAC, Horta BAC. Molecular Dynamics Simulations of PAMAM and PPI Dendrimers Using the GROMOS-Compatible 2016H66 Force Field. J Chem Inf Model 2019; 59:1444-1457. [DOI: 10.1021/acs.jcim.8b00911] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Mayk C. Ramos
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-909, Brazil
| | - Vitor A. C. Horta
- Departamento de Ciência da Computação, Universidade Federal de Juiz de Fora, Juiz de Fora, 36036-900, Brazil
| | - Bruno A. C. Horta
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro, 21941-909, Brazil
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Lonardi A, Oborský P, Hünenberger PH. Solvent-Modulated Influence of Intramolecular Hydrogen-Bonding on the Conformational Properties of the Hydroxymethyl Group in Glucose and Galactose: A Molecular Dynamics Simulation Study. Helv Chim Acta 2016. [DOI: 10.1002/hlca.201600158] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Affiliation(s)
- Alice Lonardi
- Laboratory of Physical Chemistry; ETH Hönggerberg; HCI; CH-8093 Zürich Switzerland
| | - Pavel Oborský
- Laboratory of Physical Chemistry; ETH Hönggerberg; HCI; CH-8093 Zürich Switzerland
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Horta BAC, Merz PT, Fuchs PFJ, Dolenc J, Riniker S, Hünenberger PH. A GROMOS-Compatible Force Field for Small Organic Molecules in the Condensed Phase: The 2016H66 Parameter Set. J Chem Theory Comput 2016; 12:3825-50. [DOI: 10.1021/acs.jctc.6b00187] [Citation(s) in RCA: 88] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bruno A. C. Horta
- Laboratory
of Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
- Instituto de Química, Universidade Federal do Rio de Janeiro, Rio de Janeiro 21941-909, Brazil
| | - Pascal T. Merz
- Laboratory
of Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Patrick F. J. Fuchs
- Institut Jacques Monod, UMR 7592 CNRS, Université Paris-Diderot, Sorbonne Paris Cité, F-75205 Paris, France
| | - Jozica Dolenc
- Laboratory
of Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
- Chemistry,
Biology and Pharmacy Information Center, ETH Zürich, CH-8093 Zürich, Switzerland
| | - Sereina Riniker
- Laboratory
of Physical Chemistry, ETH Zürich, CH-8093 Zürich, Switzerland
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Laner M, Hünenberger PH. Phase-transition properties of glycerol–dipalmitate lipid bilayers investigated using molecular dynamics simulation. J Mol Graph Model 2015; 59:136-47. [DOI: 10.1016/j.jmgm.2015.04.012] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Revised: 04/21/2015] [Accepted: 04/22/2015] [Indexed: 11/29/2022]
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Effect of methanol on the phase-transition properties of glycerol-monopalmitate lipid bilayers investigated using molecular dynamics simulations: In quest of the biphasic effect. J Mol Graph Model 2015; 55:85-104. [DOI: 10.1016/j.jmgm.2014.10.017] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/29/2014] [Accepted: 10/30/2014] [Indexed: 11/21/2022]
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Ogata K, Uchida W, Nakamura S. Understanding Thermal Phases in Atomic Detail by All-Atom Molecular-Dynamics Simulation of a Phospholipid Bilayer. J Phys Chem B 2014; 118:14353-65. [DOI: 10.1021/jp504684h] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Koji Ogata
- Nakamura
Laboratory, RIKEN Innovation Center, 2-1 Hirosa-wa, Wako, Saitama, Japan 351-0198
| | - Waka Uchida
- Nakamura
Laboratory, RIKEN Innovation Center, 2-1 Hirosa-wa, Wako, Saitama, Japan 351-0198
- Department
of Biomolecular Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, Kanagawa Japan, 226-8503
| | - Shinichiro Nakamura
- Nakamura
Laboratory, RIKEN Innovation Center, 2-1 Hirosa-wa, Wako, Saitama, Japan 351-0198
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Laner M, Horta BAC, Hünenberger PH. Long-timescale motions in glycerol-monopalmitate lipid bilayers investigated using molecular dynamics simulation. J Mol Graph Model 2014; 55:48-64. [PMID: 25437095 DOI: 10.1016/j.jmgm.2014.10.016] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2014] [Revised: 10/28/2014] [Accepted: 10/30/2014] [Indexed: 10/24/2022]
Abstract
The occurrence of long-timescale motions in glycerol-1-monopalmitate (GMP) lipid bilayers is investigated based on previously reported 600 ns molecular dynamics simulations of a 2×8×8 GMP bilayer patch in the temperature range 302-338 K, performed at three different hydration levels, or in the presence of the cosolutes methanol or trehalose at three different concentrations. The types of long-timescale motions considered are: (i) the possible phase transitions; (ii) the precession of the relative collective tilt-angle of the two leaflets in the gel phase; (iii) the trans-gauche isomerization of the dihedral angles within the lipid aliphatic tails; and (iv) the flipping of single lipids across the two leaflets. The results provide a picture of GMP bilayers involving a rich spectrum of events occurring on a wide range of timescales, from the 100-ps range isomerization of single dihedral angles, via the 100-ns range of tilt precession motions, to the multi-μs range of phase transitions and lipid-flipping events.
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Affiliation(s)
- Monika Laner
- Laboratory of Physical Chemistry, ETH Zürich, Zürich, Switzerland.
| | - Bruno A C Horta
- Laboratory of Physical Chemistry, ETH Zürich, Zürich, Switzerland; Dpto. de Engenharia Elétrica, PUC-Rio, Rio de Janeiro, Brazil; Dpto. de Ciências Biológicas, UEZO, Rio de Janeiro, Brazil.
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Effect of the cosolutes trehalose and methanol on the equilibrium and phase-transition properties of glycerol-monopalmitate lipid bilayers investigated using molecular dynamics simulations. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2014; 43:517-44. [DOI: 10.1007/s00249-014-0982-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 07/16/2014] [Accepted: 07/24/2014] [Indexed: 10/24/2022]
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