1
|
Torralba J, de la Arada I, Partida-Hanon A, Rujas E, Arribas M, Insausti S, Valotteau C, Valle J, Andreu D, Caaveiro JMM, Jiménez MA, Apellániz B, Redondo-Morata L, Nieva JL. Molecular recognition of a membrane-anchored HIV-1 pan-neutralizing epitope. Commun Biol 2022; 5:1265. [DOI: 10.1038/s42003-022-04219-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 11/03/2022] [Indexed: 11/19/2022] Open
Abstract
AbstractAntibodies against the carboxy-terminal section of the membrane-proximal external region (C-MPER) of the HIV-1 envelope glycoprotein (Env) are considered as nearly pan-neutralizing. Development of vaccines capable of producing analogous broadly neutralizing antibodies requires deep understanding of the mechanism that underlies C-MPER recognition in membranes. Here, we use the archetypic 10E8 antibody and a variety of biophysical techniques including single-molecule approaches to study the molecular recognition of C-MPER in membrane mimetics. In contrast to the assumption that an interfacial MPER helix embodies the entire C-MPER epitope recognized by 10E8, our data indicate that transmembrane domain (TMD) residues contribute to binding affinity and specificity. Moreover, anchoring to membrane the helical C-MPER epitope through the TMD augments antibody binding affinity and relieves the effects exerted by the interfacial MPER helix on the mechanical stability of the lipid bilayer. These observations support that addition of TMD residues may result in more efficient and stable anti-MPER vaccines.
Collapse
|
2
|
Heller WT. Small-Angle Neutron Scattering for Studying Lipid Bilayer Membranes. Biomolecules 2022; 12:1591. [PMID: 36358941 PMCID: PMC9687511 DOI: 10.3390/biom12111591] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/18/2022] [Accepted: 10/26/2022] [Indexed: 09/23/2023] Open
Abstract
Small-angle neutron scattering (SANS) is a powerful tool for studying biological membranes and model lipid bilayer membranes. The length scales probed by SANS, being from 1 nm to over 100 nm, are well-matched to the relevant length scales of the bilayer, particularly when it is in the form of a vesicle. However, it is the ability of SANS to differentiate between isotopes of hydrogen as well as the availability of deuterium labeled lipids that truly enable SANS to reveal details of membranes that are not accessible with the use of other techniques, such as small-angle X-ray scattering. In this work, an overview of the use of SANS for studying unilamellar lipid bilayer vesicles is presented. The technique is briefly presented, and the power of selective deuteration and contrast variation methods is discussed. Approaches to modeling SANS data from unilamellar lipid bilayer vesicles are presented. Finally, recent examples are discussed. While the emphasis is on studies of unilamellar vesicles, examples of the use of SANS to study intact cells are also presented.
Collapse
Affiliation(s)
- William T Heller
- Neutron Scattering Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA
| |
Collapse
|
3
|
Pogozheva ID, Armstrong GA, Kong L, Hartnagel TJ, Carpino CA, Gee SE, Picarello DM, Rubin AS, Lee J, Park S, Lomize AL, Im W. Comparative Molecular Dynamics Simulation Studies of Realistic Eukaryotic, Prokaryotic, and Archaeal Membranes. J Chem Inf Model 2022; 62:1036-1051. [PMID: 35167752 DOI: 10.1021/acs.jcim.1c01514] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
We present a comparative all-atom molecular dynamics simulation study of 18 biomembrane systems with lipid compositions corresponding to eukaryotic, bacterial, and archaebacterial membranes together with three single-component lipid bilayers. A total of 105 lipid types used in this study include diverse sterols and glycerol-based lipids with acyl chains of various lengths, unsaturation degrees, and branched or cyclic moieties. Our comparative analysis provides deeper insight into the influences of sterols and lipid unsaturation on the structural and mechanical properties of these biomembranes, including water permeation into the membrane hydrocarbon core. For sterol-containing membranes, sterol fraction is correlated with the membrane thickness, the area compressibility modulus, and lipid order but anticorrelated with the area per lipid and sterol tilt angles. Similarly, for all 18 biomembranes, lipid order is correlated with the membrane thickness and area compressibility modulus. Sterols and lipid unsaturation produce opposite effects on membrane thickness, but only sterols influence water permeation into the membrane. All membrane systems are accessible for public use in CHARMM-GUI Archive. They can be used as templates to expedite future modeling of realistic cell membranes with transmembrane and peripheral membrane proteins to study their structure, dynamics, molecular interactions, and function in a nativelike membrane environment.
Collapse
Affiliation(s)
- Irina D Pogozheva
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Grant A Armstrong
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Lingyang Kong
- Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Timothy J Hartnagel
- Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Carly A Carpino
- Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Stephen E Gee
- Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Danielle M Picarello
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Amanda S Rubin
- Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Jumin Lee
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Soohyung Park
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| | - Andrei L Lomize
- Department of Medicinal Chemistry, College of Pharmacy, University of Michigan, Ann Arbor, Michigan 48109, United States
| | - Wonpil Im
- Department of Biological Sciences, Lehigh University, Bethlehem, Pennsylvania 18015, United States.,Department of Bioengineering, Lehigh University, Bethlehem, Pennsylvania 18015, United States.,Department of Chemistry, Lehigh University, Bethlehem, Pennsylvania 18015, United States
| |
Collapse
|
4
|
Danielczak B, Rasche M, Lenz J, Pérez Patallo E, Weyrauch S, Mahler F, Agbadaola MT, Meister A, Babalola JO, Vargas C, Kolar C, Keller S. A bioinspired glycopolymer for capturing membrane proteins in native-like lipid-bilayer nanodiscs. NANOSCALE 2022; 14:1855-1867. [PMID: 35040850 DOI: 10.1039/d1nr03811g] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Amphiphilic copolymers that directly extract membrane proteins and lipids from cellular membranes to form nanodiscs combine the advantages of harsher membrane mimics with those of a native-like membrane environment. Among the few commercial polymers that are capable of forming nanodiscs, alternating diisobutylene/maleic acid (DIBMA) copolymers have gained considerable popularity as gentle and UV-transparent alternatives to aromatic polymers. However, their moderate hydrophobicities and high electric charge densities render all existing aliphatic copolymers rather inefficient under near-physiological conditions. Here, we introduce Glyco-DIBMA, a bioinspired glycopolymer that possesses increased hydrophobicity and reduced charge density but nevertheless retains excellent solubility in aqueous solutions. Glyco-DIBMA outperforms established aliphatic copolymers in that it solubilizes lipid vesicles of various compositions much more efficiently, thereby furnishing smaller, more narrowly distributed nanodiscs that preserve a bilayer architecture and exhibit rapid lipid exchange. We demonstrate the superior performance of Glyco-DIBMA in preparative and analytical applications by extracting a broad range of integral membrane proteins from cellular membranes and further by purifying a membrane-embedded voltage-gated K+ channel, which was fluorescently labeled and analyzed with the aid of microfluidic diffusional sizing (MDS) directly within native-like lipid-bilayer nanodiscs.
Collapse
Affiliation(s)
- Bartholomäus Danielczak
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 13, 67663 Kaiserslautern, Germany
| | - Marie Rasche
- Glycon Biochemicals GmbH, Im Biotechnologiepark TGZ 1, 14943 Luckenwalde, Germany
| | - Julia Lenz
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 13, 67663 Kaiserslautern, Germany
| | - Eugenio Pérez Patallo
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 13, 67663 Kaiserslautern, Germany
| | - Sophie Weyrauch
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 13, 67663 Kaiserslautern, Germany
| | - Florian Mahler
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 13, 67663 Kaiserslautern, Germany
| | - Michael Tope Agbadaola
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 13, 67663 Kaiserslautern, Germany
- Department of Chemistry, University of Ibadan, 200284, Ibadan, Nigeria
| | - Annette Meister
- Institute of Biochemistry and Biotechnology, and ZIK HALOmem, Martin Luther University Halle-Wittenberg, Kurt-Mothes-Str. 3a, 06120 Halle (Saale), Germany
| | | | - Carolyn Vargas
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 13, 67663 Kaiserslautern, Germany
- Biophysics, Institute of Molecular Biosciences (IMB), NAWI Graz, University of Graz, Humboldtstr. 50/III, 8010 Graz, Austria.
- Field of Excellence BioHealth, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Cenek Kolar
- Glycon Biochemicals GmbH, Im Biotechnologiepark TGZ 1, 14943 Luckenwalde, Germany
| | - Sandro Keller
- Molecular Biophysics, Technische Universität Kaiserslautern (TUK), Erwin-Schrödinger-Str. 13, 67663 Kaiserslautern, Germany
- Biophysics, Institute of Molecular Biosciences (IMB), NAWI Graz, University of Graz, Humboldtstr. 50/III, 8010 Graz, Austria.
- Field of Excellence BioHealth, University of Graz, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| |
Collapse
|
5
|
Abstract
Abstract
In the review we describe a method for concentration of anionic liposomes with encapsulated water-soluble substances within a small volume via electrostatic liposome adsorption on the surface of polymer particles with grafted cationic chains (spherical polycationic brushes), or cationic microgel particles. Dozens of intact liposomes can be bound to each polymer particle, the resulting polymer/liposome complex does not dissociate into the original components in a physiological solution. This allows fabrication of multi-liposomal complexes (MLCs) with a required ratio of encapsulated substances. Two approaches are discussed for the synthesis of stimuli-sensitive MLCs. The first is to incorporate the conformation switch, morpholinocyclohexanol-based lipid, into the liposomal membrane thus forming pH-sensitive liposomes capable of releasing their cargo when acidifying the surrounding solution. These liposomes complexed with the brushes release encapsulated substances much faster than the uncomplexed liposomes. The second is to adsorb liposomes on cationic thermo-responsive microgels. The resulting MLCs contracts upon heating over a volume phase transition temperature from the swollen to the collapsed state of microgel, thus causing the adsorbed liposomes to change drastically their morphology and release an encapsulated substance. Complexation of anionic liposomes with chitosan microgels and polylactide micelles gives MLCs which degrade in the presence of enzymes down to small particles, 10–15 nm in diameter. A novel promising approach suggests that immobilized liposomes can act as a capacious depot for biologically active compounds and ensure their controllable leakage to surrounding solution.
Collapse
Affiliation(s)
- Alexander A. Yaroslavov
- Lomonosov Moscow State University , Department of Chemistry , Leninskie Gory 1-3 , Moscow 119991 , Russian Federation
| | - Andrey V. Sybachin
- Lomonosov Moscow State University , Department of Chemistry , Leninskie Gory 1-3 , Moscow 119991 , Russian Federation
| |
Collapse
|
6
|
Bozelli JC, Yune J, Dang X, Narayana JL, Wang G, Epand RM. Membrane activity of two short Trp-rich amphipathic peptides. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183280. [PMID: 32220553 DOI: 10.1016/j.bbamem.2020.183280] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 03/09/2020] [Accepted: 03/18/2020] [Indexed: 12/13/2022]
Abstract
Short linear antimicrobial peptides are attractive templates for developing new antibiotics. Here, it is described a study of the interaction between two short Trp-rich peptides, horine and verine-L, and model membranes. Isothermal titration calorimetry studies showed that the affinity of these peptides towards large unilamellar vesicles (LUV) having a lipid composition mimicking the lipid composition of S. aureus membranes is ca. 30-fold higher than that towards E. coli mimetics. The former interaction is driven by enthalpy and entropy, while the latter case is driven by entropy, suggesting differences in the forces that play a role in the binding to the two types of model membranes. Upon membrane binding the peptides acquired different conformations according to circular dichroism (CD) studies; however, in both cases CD studies indicated stacked W-residues. Peptide-induced membrane permeabilization, lipid flip-flop, molecular packing at the membrane-water interface, and lateral lipid segregation were observed in all cases. However, the extent of these peptide-induced changes on membrane properties was always higher in S. aureus than E. coli mimetics. Both peptides seem to act via a similar mechanism of membrane permeabilization of S. aureus membrane mimetics, while their mechanisms seem to differ in the case of E. coli. This may be the result of differences in both the peptides´ structure and the membrane lipid composition between both types of bacteria.
Collapse
Affiliation(s)
- José C Bozelli
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 4K1, Canada
| | - Jenny Yune
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 4K1, Canada
| | - Xiangli Dang
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, NE 68198-5990, USA
| | - Jayaram Lakshmaiah Narayana
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, NE 68198-5990, USA
| | - Guangshun Wang
- Department of Pathology and Microbiology, College of Medicine, University of Nebraska Medical Center, 985900 Nebraska Medical Center, Omaha, NE 68198-5990, USA
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Health Sciences Centre, Hamilton, ON L8S 4K1, Canada.
| |
Collapse
|
7
|
Lee TH, Sani MA, Overall S, Separovic F, Aguilar MI. Effect of phosphatidylcholine bilayer thickness and molecular order on the binding of the antimicrobial peptide maculatin 1.1. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2018; 1860:300-309. [DOI: 10.1016/j.bbamem.2017.10.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2017] [Revised: 09/18/2017] [Accepted: 10/08/2017] [Indexed: 01/01/2023]
|
8
|
Su CJ, Lee MT, Liao KF, Shih O, Jeng US. Interplay of entropy and enthalpy in peptide binding to zwitterionic phospholipid membranes as revealed from membrane thinning. Phys Chem Chem Phys 2018; 20:26830-26836. [DOI: 10.1039/c8cp02861c] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Melittin binding affinity enhances linearly with the membrane thermal thinning rate of the three phosphocholine-based ULVs of diCn:1PC.
Collapse
Affiliation(s)
- Chun-Jen Su
- National Synchrotron Radiation Research Center
- Hsinchu Science Park
- Hsinchu 30076
- Taiwan
| | - Ming-Tao Lee
- National Synchrotron Radiation Research Center
- Hsinchu Science Park
- Hsinchu 30076
- Taiwan
| | - Kuei-Fen Liao
- National Synchrotron Radiation Research Center
- Hsinchu Science Park
- Hsinchu 30076
- Taiwan
| | - Orion Shih
- National Synchrotron Radiation Research Center
- Hsinchu Science Park
- Hsinchu 30076
- Taiwan
| | - U-Ser Jeng
- National Synchrotron Radiation Research Center
- Hsinchu Science Park
- Hsinchu 30076
- Taiwan
- Department of Chemical Engineering
| |
Collapse
|
9
|
Tristram-Nagle S. Use of X-Ray and Neutron Scattering Methods with Volume Measurements to Determine Lipid Bilayer Structure and Number of Water Molecules/Lipid. Subcell Biochem 2015; 71:17-43. [PMID: 26438260 DOI: 10.1007/978-3-319-19060-0_2] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
In this chapter I begin with a historical perspective of membrane models, starting in the early twentieth century. As these membrane models evolved, so did experiments to characterize the structure and water content of purified lipid bilayers. The wide-spread use of the X-ray gravimetric, or Luzzati method, is critically discussed. The main motivation of the gravimetric technique is to determine the number of water molecules/lipid, n(W), and then derive other important structural quantities, such as area/lipid, A(L). Subsequent experiments from the Nagle/Tristram-Nagle laboratory using X-ray and neutron scattering, first determine A(L) and then calculate n(W), using molecular lipid V(L) and water V(W) volumes. This chapter describes the details of our volume experiments to carefully measure V(L). Our results also determine n(W)', the steric water associated with the lipid headgroup, and how our calculated value compares to many literature values of tightly-associated headgroup water.
Collapse
Affiliation(s)
- Stephanie Tristram-Nagle
- Biological Physics Group, Physics Department, Carnegie Mellon University, Pittsburgh, PA, 15213, USA.
| |
Collapse
|
10
|
Gallová J, Klacsová M, Devínsky F, Balgavý P. Partial volumes of cholesterol and monounsaturated diacylphosphatidylcholines in mixed bilayers. Chem Phys Lipids 2015; 190:1-8. [DOI: 10.1016/j.chemphyslip.2015.06.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/20/2015] [Accepted: 06/15/2015] [Indexed: 10/23/2022]
|
11
|
Mannock DA, Benesch MG, Lewis RN, McElhaney RN. A comparative calorimetric and spectroscopic study of the effects of cholesterol and of the plant sterols β-sitosterol and stigmasterol on the thermotropic phase behavior and organization of dipalmitoylphosphatidylcholine bilayer membranes. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:1629-38. [DOI: 10.1016/j.bbamem.2015.04.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 04/08/2015] [Accepted: 04/15/2015] [Indexed: 12/31/2022]
|
12
|
Saleem Q, Zhang Z, Gradinaru CC, Macdonald PM. Liposome-coated hydrogel spheres: delivery vehicles with tandem release from distinct compartments. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2013; 29:14603-14612. [PMID: 24156402 DOI: 10.1021/la402796k] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
We have fabricated unilamellar lipid bilayer VESicle-COated hydrogel spheres (VESCOgels) by carbodiimide-mediated coupling of liposomes bearing surface amines to core-shell hydrogel spheres bearing surface carboxyls. The amine-containing moiety, 3-O (2-aminoethoxyethyloxyethyl)carbamyl cholesterol (AECHO), was incorporated into large unilamellar vesicles (LUVs), diameter ∼100 nm, composed of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC). The hydrogel, diameter ∼ 1 μm, consisted of a core of poly(N-isopropyl acrylamide) (pNIPAM) and a shell of p(NIPAM-co-acrylic acid (AA)). Activation of these surface-displayed carboxyls with N-hydroxysuccinimidyl (NHS) esters permitted amine coupling upon addition of AECHO-containing POPC LUVs. Bilayer integrity of the hydrogel-bound LUVs was maintained, and fusion of LUVs did not occur. Fluorescence assays of the release of cobalt-calcein trapped within hydrogel-bound LUVs and of sodium fluorescein trapped within the hydrogel itself showed that each compartment retained its distinct release attributes: fast release from the microgel and slow release from the LUVs. It is envisioned that VESCOgels will be useful, therefore, in applications requiring temporally controlled delivery of distinct drugs.
Collapse
Affiliation(s)
- Qasim Saleem
- Department of Chemistry and ‡Department of Physics, University of Toronto , Toronto, Ontario, Canada
| | | | | | | |
Collapse
|
13
|
Membrane physical properties influence transmembrane helix formation. Proc Natl Acad Sci U S A 2012; 109:14422-7. [PMID: 22908237 DOI: 10.1073/pnas.1212665109] [Citation(s) in RCA: 61] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The pHLIP peptide has three states: (I) soluble in aqueous buffer, (II) bound to the bilayer surface at neutral pH, and (III) inserted as a transmembrane (TM) helix at acidic pH. The membrane insertion of pHLIP at low pH can be used to target the acidic tissues characteristic of different diseases, such as cancer. We find that the α-helix content of state II depends on lipid acyl chain length but not cholesterol, suggesting the helicity of the bound state may be controlled by the bilayer elastic bending modulus. Experiments with the P20G variant show the proline residue in pHLIP reduces the α-helix content of both states II and III. We also observe that the membrane insertion pKa is influenced by membrane physical properties, following a biphasic pattern similar to the membrane thickness optima observed for the function of eukaryotic membrane proteins. Because tumor cells exhibit altered membrane fluidity, we suggest this might influence pHLIP tumor targeting. We used a cell insertion assay to determine the pKa in live cells, observing that the properties in liposomes held in the more complex plasma membrane. Our results show that the formation of a TM helix is modulated by both the conformational propensities of the peptide and the physical properties of the bilayer. These results suggest a physical role for helix-membrane interactions in optimizing the function of more complex TM proteins.
Collapse
|
14
|
|
15
|
Yi Z, Nagao M, Bossev DP. Effect of charged lidocaine on static and dynamic properties of model bio-membranes. Biophys Chem 2012; 160:20-7. [DOI: 10.1016/j.bpc.2011.08.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Revised: 08/28/2011] [Accepted: 08/30/2011] [Indexed: 11/28/2022]
|
16
|
Klacsová M, Bulacu M, Kučerka N, Uhríková D, Teixeira J, Marrink S, Balgavý P. The effect of aliphatic alcohols on fluid bilayers in unilamellar DOPC vesicles — A small-angle neutron scattering and molecular dynamics study. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2011; 1808:2136-46. [DOI: 10.1016/j.bbamem.2011.04.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Revised: 03/30/2011] [Accepted: 04/21/2011] [Indexed: 10/18/2022]
|
17
|
Gallová J, Uhríková D, Kučerka N, Svorková M, Funari SS, Murugova TN, Almásy L, Mazúr M, Balgavý P. Influence of cholesterol and β-sitosterol on the structure of EYPC bilayers. J Membr Biol 2011; 243:1-13. [PMID: 21814861 DOI: 10.1007/s00232-011-9387-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2010] [Accepted: 07/13/2011] [Indexed: 11/28/2022]
Abstract
The influence of cholesterol and β-sitosterol on egg yolk phosphatidylcholine (EYPC) bilayers is compared. Different interactions of these sterols with EYPC bilayers were observed using X-ray diffraction. Cholesterol was miscible with EYPC in the studied concentration range (0-50 mol%), but crystallization of β-sitosterol in EYPC bilayers was observed at X ≥ 41 mol% as detected by X-ray diffraction. Moreover, the repeat distance (d) of the lamellar phase was similar upon addition of the two sterols up to mole fraction 17%, while for X ≥ 17 mol% it became higher in the presence of β-sitosterol compared to cholesterol. SANS data on suspensions of unilamellar vesicles showed that both cholesterol and β-sitosterol similarly increase the EYPC bilayer thickness. Cholesterol in amounts above 33 mol% decreased the interlamellar water layer thickness, probably due to "stiffening" of the bilayer. This effect was not manifested by β-sitosterol, in particular due to the lower solubility of β-sitosterol in EYPC bilayers. Applying the formalism of partial molecular areas, it is shown that the condensing effect of both sterols on the EYPC area at the lipid-water interface is small, if any. The parameters of ESR spectra of spin labels localized in different regions of the EYPC bilayer did not reveal any differences between the effects of cholesterol and β-sitosterol in the range of full miscibility.
Collapse
Affiliation(s)
- Jana Gallová
- Department of Physical Chemistry of Drugs, Faculty of Pharmacy, Comenius University, Odbojárov 10, 832 32 Bratislava, Slovakia.
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Use of small angle neutron scattering to study the interaction of angiotensin II with model membranes. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2011; 40:687-98. [DOI: 10.1007/s00249-011-0675-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2010] [Revised: 12/30/2010] [Accepted: 01/06/2011] [Indexed: 01/17/2023]
|
19
|
Gallová J, Uhríková D, Kučerka N, Teixeira J, Balgavý P. Partial area of cholesterol in monounsaturated diacylphosphatidylcholine bilayers. Chem Phys Lipids 2010; 163:765-70. [DOI: 10.1016/j.chemphyslip.2010.08.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Revised: 08/03/2010] [Accepted: 08/12/2010] [Indexed: 11/16/2022]
|
20
|
Gallová J, Uhríková D, Kučerka N, Doktorovová S, Funari SS, Teixeira J, Balgavý P. The effects of cholesterol and β-sitosterol on the structure of saturated diacylphosphatidylcholine bilayers. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2010; 40:153-63. [DOI: 10.1007/s00249-010-0635-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Revised: 09/29/2010] [Accepted: 09/30/2010] [Indexed: 11/24/2022]
|
21
|
Boggara MB, Krishnamoorti R. Small-angle neutron scattering studies of phospholipid-NSAID adducts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2010; 26:5734-5745. [PMID: 20014785 DOI: 10.1021/la903854s] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Nonsteroidal anti-inflammatory drugs (NSAIDs) are known to have strong interactions with lipid membranes. Using small-angle neutron scattering, the effect of ibuprofen, a prominent NSAID, on the radius of small unilamellar vesicles of 1,2-dimyristoyl-sn-glycero-3-phosphatidylcholine (DMPC) and their bilayer structure was studied systematically as a function of pH (ranging from 2 to 8) and drug-to-lipid mole ratio (from 0/1 to 0.62/1 mol/mol). Ibuprofen with a pK(a) of approximately 4.6 was found to significantly affect the bilayer structure at all pH values, irrespective of the charge state of the drug. At low pH values, the drug reduces the bilayer thickness, induces fluid-like behavior, and changes headgroup hydration. The incorporation of the drug in the lipid bilayer while affecting the local bilayer structure and hydration of the lipid does not affect the overall stability of the vesicle dispersions over the pH range studied.
Collapse
Affiliation(s)
- Mohan Babu Boggara
- Department of Chemical and Biomolecular Engineering, University of Houston, Houston, Texas 77204, USA
| | | |
Collapse
|
22
|
Pfeiffer H, Klose G, Heremans K. Thermodynamic and structural behaviour of equimolar POPC/CnE4 (n=8, 12, 16) mixtures by sorption gravimetry, 2H NMR spectroscopy and X-ray diffraction. Chem Phys Lipids 2010; 163:318-28. [PMID: 20060820 DOI: 10.1016/j.chemphyslip.2009.12.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Revised: 12/02/2009] [Accepted: 12/14/2009] [Indexed: 10/20/2022]
Abstract
The hydration behaviour of equimolar mixtures of phospholipids and nonionic surfactants with different chain length was investigated by gravimetric sorption, NMR spectroscopy and X-ray diffraction. At the most hydration degrees investigated, the incorporation of nonionic surfactants in a phospholipid bilayer leads to an increase of the hydrophilicity, which can be shown by the presence of excess hydration. The increased hydrophilicity could be explained by the excavation of additional water binding sites due to the "dilution" of the dipole field of the phospholipid bilayer. Another related contribution arises from the increase of the accessible surface area due to the increase of gauche conformers that result from the steric mismatch when surfactants are incorporated into the phospholipid matrix. (2)H NMR spectroscopy was used to determine the quadrupolar splitting representing a measure of the order state of water. The swelling behaviour could be assessed by small-angle X-ray diffraction. (31)P NMR spectroscopy was applied for the assignment of phase structures to the respective hydration range.
Collapse
Affiliation(s)
- H Pfeiffer
- Katholieke Universiteit Leuven, Department of Metallurgy and Materials Engineering, B-3001 Leuven, Belgium.
| | | | | |
Collapse
|
23
|
Kučerka N, Nieh MP, Katsaras J. Small-Angle Scattering from Homogenous and Heterogeneous Lipid Bilayers. ADVANCES IN PLANAR LIPID BILAYERS AND LIPOSOMES 2010. [DOI: 10.1016/b978-0-12-381266-7.00008-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
24
|
Ramadurai S, Holt A, Krasnikov V, van den Bogaart G, Killian JA, Poolman B. Lateral diffusion of membrane proteins. J Am Chem Soc 2009; 131:12650-6. [PMID: 19673517 DOI: 10.1021/ja902853g] [Citation(s) in RCA: 263] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We measured the lateral mobility of integral membrane proteins reconstituted in giant unilamellar vesicles (GUVs), using fluorescence correlation spectroscopy. Receptor, channel, and transporter proteins with 1-36 transmembrane segments (lateral radii ranging from 0.5 to 4 nm) and a alpha-helical peptide (radius of 0.5 nm) were fluorescently labeled and incorporated into GUVs. At low protein-to-lipid ratios (i.e., 10-100 proteins per microm(2) of membrane surface), the diffusion coefficient D displayed a weak dependence on the hydrodynamic radius (R) of the proteins [D scaled with ln(1/R)], consistent with the Saffman-Delbruck model. At higher protein-to lipid ratios (up to 3000 microm(-2)), the lateral diffusion coefficient of the molecules decreased linearly with increasing the protein concentration in the membrane. The implications of our findings for protein mobility in biological membranes (protein crowding of approximately 25,000 microm(-2)) and use of diffusion measurements for protein geometry (size, oligomerization) determinations are discussed.
Collapse
Affiliation(s)
- Sivaramakrishnan Ramadurai
- Department of Biochemistry, Groningen Biomolecular science and Biotechnology Institute & Zernike Institute of Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | | | | | | | | | | |
Collapse
|
25
|
Kucerka N, Gallová J, Uhríková D, Balgavý P, Bulacu M, Marrink SJ, Katsaras J. Areas of monounsaturated diacylphosphatidylcholines. Biophys J 2009; 97:1926-32. [PMID: 19804723 DOI: 10.1016/j.bpj.2009.06.050] [Citation(s) in RCA: 80] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2009] [Revised: 06/17/2009] [Accepted: 06/23/2009] [Indexed: 11/17/2022] Open
Abstract
We have studied the structural properties of monounsaturated diacylphosphatidylcholine lipid bilayers (i.e., diCn:1PC, where n = 14, 16, 18, 20, 22, and 24 is the number of acyl chain carbons). High-resolution x-ray scattering data were analyzed in conjunction with contrast-varied neutron scattering data using a technique we recently developed. Analyses of the data show that the manner by which bilayer thickness increases with increasing n in monounsaturated diacylphosphatidylcholines is dependent on the double bond's position. For commonly available monounsaturated diacylphosphatidylcholines, this results in the nonlinear behavior of both bilayer thickness and lipid area, whereas for diC18:1PC bilayers, lipid area assumes a maximum value. It is worthwhile to note that compared to previous data, our results indicate that lipid areas are smaller by approximately 10%. This observation highlights the need to revisit lipid areas, as they are often used in comparisons with molecular dynamics simulations. Moreover, simulators are encouraged to compare their results not only to x-ray scattering data, but to neutron data as well.
Collapse
Affiliation(s)
- Norbert Kucerka
- Canadian Neutron Beam Centre, National Research Council, Chalk River, Ontario, Canada
| | | | | | | | | | | | | |
Collapse
|
26
|
Kucerka N, Nieh MP, Katsaras J. Asymmetric distribution of cholesterol in unilamellar vesicles of monounsaturated phospholipids. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:13522-13527. [PMID: 19678653 DOI: 10.1021/la9020299] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We have studied the effect of cholesterol on curved bilayers using 600 A unilamellar vesicles made of monounsaturated lipids. From small-angle X-ray scattering experiments we were able to detect an asymmetric distribution of lipid densities across certain bilayers. We discovered that, with the exception of diC24:1PC bilayers, monounsaturated diacylphosphatidylcholine lipids (diCn:1PC, n = 14, 16, 18, 20, and 22) form symmetric bilayers. However, the addition of 44 mol % cholesterol resulted in some of these bilayers (i.e., n = 14, 16, and 18) to become asymmetric, where cholesterol was found to distribute unequally between the bilayer's two leaflets. This finding is potentially of relevance to biological membranes made up of different types of lipids and whose local curvature may be dictated by lipid composition.
Collapse
Affiliation(s)
- Norbert Kucerka
- Canadian Neutron Beam Centre, National Research Council, Chalk River, Ontario K0J 1J0, Canada.
| | | | | |
Collapse
|