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Nguyen MHL, Dziura D, DiPasquale M, Castillo SR, Kelley EG, Marquardt D. Investigating the cut-off effect of n-alcohols on lipid movement: a biophysical study. SOFT MATTER 2023. [PMID: 37357554 DOI: 10.1039/d2sm01583h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/27/2023]
Abstract
Cellular membranes are responsible for absorbing the effects of external perturbants for the cell's survival. Such perturbants include small ubiquitous molecules like n-alcohols which were observed to exhibit anesthetic capabilities, with this effect tapering off at a cut-off alcohol chain length. To explain this cut-off effect and complement prior biochemical studies, we investigated a series of n-alcohols (with carbon lengths 2-18) and their impact on several bilayer properties, including lipid flip-flop, intervesicular exchange, diffusion, membrane bending rigidity and more. To this end, we employed an array of biophysical techniques such as time-resolved small angle neutron scattering (TR-SANS), small angle X-ray scattering (SAXS), all atomistic and coarse-grained molecular dynamics (MD) simulations, and calcein leakage assays. At an alcohol concentration of 30 mol% of the overall lipid content, TR-SANS showed 1-hexanol (C6OH) increased transverse lipid diffusion, i.e. flip-flop. As alcohol chain length increased from C6 to C10 and longer, lipid flip-flop slowed by factors of 5.6 to 32.2. Intervesicular lipid exchange contrasted these results with only a slight cut-off at alcohol concentrations of 30 mol% but not 10 mol%. SAXS, MD simulations, and leakage assays revealed changes to key bilayer properties, such as bilayer thickness and fluidity, that correlate well with the effects on lipid flip-flop rates. Finally, we tie our results to a defect-mediated pathway for alcohol-induced lipid flip-flop.
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Affiliation(s)
- Michael H L Nguyen
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Dominik Dziura
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Mitchell DiPasquale
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Stuart R Castillo
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Elizabeth G Kelley
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD, USA
| | - Drew Marquardt
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
- Department of Physics, University of Windsor, Windsor, Ontario, Canada.
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2
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Study of the Interaction of a Novel Semi-Synthetic Peptide with Model Lipid Membranes. MEMBRANES 2020; 10:membranes10100294. [PMID: 33086635 PMCID: PMC7603383 DOI: 10.3390/membranes10100294] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 10/14/2020] [Accepted: 10/16/2020] [Indexed: 12/31/2022]
Abstract
Most linear peptides directly interact with membranes, but the mechanisms of interaction are far from being completely understood. Here, we present an investigation of the membrane interactions of a designed peptide containing a non-natural, synthetic amino acid. We selected a nonapeptide that is reported to interact with phospholipid membranes, ALYLAIRKR, abbreviated as ALY. We designed a modified peptide (azoALY) by substituting the tyrosine residue of ALY with an antimicrobial azobenzene-bearing amino acid. Both of the peptides were examined for their ability to interact with model membranes, assessing the penetration of phospholipid monolayers, and leakage across the bilayer of large unilamellar vesicles (LUVs) and giant unilamellar vesicles (GUVs). The latter was performed in a microfluidic device in order to study the kinetics of leakage of entrapped calcein from the vesicles at the single vesicle level. Both types of vesicles were prepared from a 9:1 (mol/mol) mixture of POPC (1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) and POPG (1-palmitoyl-2-oleoyl-sn-glycero-3-phospho(1′-rac-glycerol). Calcein leakage from the vesicles was more pronounced at a low concentration in the case of azoALY than for ALY. Increased vesicle membrane disturbance in the presence of azoALY was also evident from an enzymatic assay with LUVs and entrapped horseradish peroxidase. Molecular dynamics simulations of ALY and azoALY in an anionic POPC/POPG model bilayer showed that ALY peptide only interacts with the lipid head groups. In contrast, azoALY penetrates the hydrophobic core of the bilayers causing a stronger membrane perturbation as compared to ALY, in qualitative agreement with the experimental results from the leakage assays.
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3
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Miyabe K, Senoo S, Okayasu N. Moment theory for the analytical determination of rate constants for solute permeation at the interface of spherical molecular aggregates. Electrophoresis 2019; 40:2962-2970. [PMID: 31512268 DOI: 10.1002/elps.201900182] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 09/02/2019] [Accepted: 09/05/2019] [Indexed: 11/05/2022]
Abstract
Moment equations were developed on the basis of the Einstein equation for diffusion and the random walk model to analytically determine the rate constant for the interfacial solute permeation from a bulk solvent into molecular aggregates (kin ) and the inverse rate constant from the molecular aggregates to the bulk solvent (kout ). The moment equations were in good agreement with those derived in a different manner. To demonstrate their effectiveness in one concrete example, the moment equations were used to analytically determine the values of kin and kout of three electrically neutral solutes, i.e. resorcinol, phenol, and nitrobenzene, from the first absolute (μ1A ) and second central (μ2C ) moments of their elution peaks, as measured by electrokinetic chromatography (EKC), in which the sodium dodecyl sulfate (SDS) micelles were used as a pseudostationary phase. The values of kin and kout should be determined with no chemical modifications and no physical action with the molecular aggregates because they are dynamic systems formed through weak interactions between the components. The moment analysis of the elution peak profiles measured by EKC is effective to unambiguously determine kin , kout , and the partition equilibrium constant (kin /kout ) under appropriate experimental conditions.
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Affiliation(s)
- Kanji Miyabe
- Department of Chemistry, Faculty of Science, Rikkyo University, Tokyo, Japan
| | - Shiori Senoo
- Department of Chemistry, Faculty of Science, Rikkyo University, Tokyo, Japan
| | - Nanami Okayasu
- Department of Chemistry, Faculty of Science, Rikkyo University, Tokyo, Japan
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4
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Reeßing F, Stuart MCA, Samplonius DF, Dierckx RAJO, Feringa BL, Helfrich W, Szymanski W. A light-responsive liposomal agent for MRI contrast enhancement and monitoring of cargo delivery. Chem Commun (Camb) 2019; 55:10784-10787. [DOI: 10.1039/c9cc05516a] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A liposomal MRI-probe changing relaxivity and releasing cargo upon light irradiation was developed for diagnostics and monitoring of drug delivery.
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Affiliation(s)
- F. Reeßing
- Department of Radiology
- Medical Imaging Center
- University of Groningen
- University Medical Center Groningen
- 9713GZ Groningen
| | - M. C. A. Stuart
- Stratingh Institute for Chemistry
- University of Groningen
- 9747 AG Groningen
- The Netherlands
| | - D. F. Samplonius
- Translational Surgical Oncology
- Department of Surgery
- University of Groningen
- University Medical Center Groningen
- 9713GZ Groningen
| | - R. A. J. O. Dierckx
- Department of Radiology
- Medical Imaging Center
- University of Groningen
- University Medical Center Groningen
- 9713GZ Groningen
| | - B. L. Feringa
- Department of Radiology
- Medical Imaging Center
- University of Groningen
- University Medical Center Groningen
- 9713GZ Groningen
| | - W. Helfrich
- Translational Surgical Oncology
- Department of Surgery
- University of Groningen
- University Medical Center Groningen
- 9713GZ Groningen
| | - W. Szymanski
- Department of Radiology
- Medical Imaging Center
- University of Groningen
- University Medical Center Groningen
- 9713GZ Groningen
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5
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Miyabe K. Moment analysis for mass transfer kinetics at the interface of spherical molecular aggregates. J Chromatogr A 2018; 1572:172-178. [PMID: 30172357 DOI: 10.1016/j.chroma.2018.08.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/07/2018] [Accepted: 08/14/2018] [Indexed: 11/17/2022]
Abstract
New moment equations were developed on the basis of the principle of relativity for explaining some characteristics of elution peaks measured by electrokinetic chromatography (EKC) using spherical molecular aggregates. Basic equations representing mass balance and mass transfer kinetics in EKC system in a Galilean coordinate system S were transformed to those in another coordinate system S', which imaginarily moved with respect to S. Moment equations for EKC peaks in S' in the time domain were derived from the analytical solution of the modified basic equations in the Laplace domain. Moment equations for EKC peaks in S were derived from those in S' by the inverse Galilean transformation. The moment equations were used to the re-analysis of EKC data previously measured. The values of permeation rate constants of thymol at the interface of sodium dodecylsulfate micelles were fairly in agreement with those determined in a previous study. The moment equations were also used to the numerical simulation of elution peaks in EKC systems. The influence of some experimental parameters on elution peak profiles was quantitatively analyzed. The moment equations are useful for determining the rate constants of interfacial solute permeation from elution peak profiles measured by EKC.
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Affiliation(s)
- Kanji Miyabe
- Department of Chemistry, Faculty of Science, Rikkyo University, 3-34-1, Nishi-Ikebukuro, Toshima-ku, Tokyo, 171-8501, Japan.
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6
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Zhang P, Steinborn B, Lächelt U, Zahler S, Wagner E. Lipo-Oligomer Nanoformulations for Targeted Intracellular Protein Delivery. Biomacromolecules 2017. [DOI: 10.1021/acs.biomac.7b00666] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peng Zhang
- Pharmaceutical Biotechnology,
Center for System-based Drug Research Center for NanoScience (CeNS), Ludwig-Maximilians-Universität, Munich 81377, Germany
| | - Benjamin Steinborn
- Pharmaceutical Biotechnology,
Center for System-based Drug Research Center for NanoScience (CeNS), Ludwig-Maximilians-Universität, Munich 81377, Germany
| | - Ulrich Lächelt
- Pharmaceutical Biotechnology,
Center for System-based Drug Research Center for NanoScience (CeNS), Ludwig-Maximilians-Universität, Munich 81377, Germany
| | - Stefan Zahler
- Pharmaceutical Biotechnology,
Center for System-based Drug Research Center for NanoScience (CeNS), Ludwig-Maximilians-Universität, Munich 81377, Germany
| | - Ernst Wagner
- Pharmaceutical Biotechnology,
Center for System-based Drug Research Center for NanoScience (CeNS), Ludwig-Maximilians-Universität, Munich 81377, Germany
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7
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Kolesinska B, Eyer K, Robinson T, Dittrich PS, Beck AK, Seebach D, Walde P. Interaction of β(3) /β(2) -peptides, consisting of Val-Ala-Leu segments, with POPC giant unilamellar vesicles (GUVs) and white blood cancer cells (U937)--a new type of cell-penetrating peptides, and a surprising chain-length dependence of their vesicle- and cell-lysing activity. Chem Biodivers 2016; 12:697-732. [PMID: 26010661 DOI: 10.1002/cbdv.201500085] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Indexed: 01/28/2023]
Abstract
Many years ago, β(2) /β(3) -peptides, consisting of alternatively arranged β(2) - and β(3) h-amino-acid residues, have been found to undergo folding to a unique type of helix, the 10/12-helix, and to exhibit non-polar, lipophilic properties (Helv. Chim. Acta 1997, 80, 2033). We have now synthesized such 'mixed' hexa-, nona-, dodeca-, and octadecapeptides, consisting of Val-Ala-Leu triads, with N-terminal fluorescein (FAM) labels, i.e., 1-4, and studied their interactions with POPC (=1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine) giant unilamellar vesicles (GUVs) and with human white blood cancer cells U937. The methods used were microfluidic technology, fluorescence correlation spectroscopy (FCS), a flow-cytometry assay, a membrane-toxicity assay with the dehydrogenase G6PDH as enzymatic reporter, and visual microscopy observations. All β(3) /β(2) -peptide derivatives penetrate the GUVs and/or the cells. As shown with the isomeric β(3) /β(2) -, β(3) -, and β(2) -nonamers, 2, 5, and 6, respectively, the derivatives 5 and 6 consisting exclusively of β(3) - or β(2) -amino-acid residues, respectively, interact neither with the vesicles nor with the cells. Depending on the method of investigation and on the pretreatment of the cells, the β(3) /β(2) -nonamer and/or the β(3) /β(2) -dodecamer derivative, 2 and/or 3, respectively, cause a surprising disintegration or lysis of the GUVs and cells, comparable with the action of tensides, viral fusion peptides, and host-defense antimicrobial peptides. Possible sources of the chain-length-dependent destructive potential of the β(3) /β(2) -nona- and β(3) /β(2) -dodecapeptide derivatives, and a possible relationship with the phosphate-to-phosphate and hydrocarbon thicknesses of GUVs, and eukaryotic cells are discussed. Further investigations with other types of GUVs and of eukaryotic or prokaryotic cells will be necessary to elucidate the mechanism(s) of interaction of 'mixed' β(3) /β(2) -peptides with membranes and to evaluate possible biomedical applications.
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Affiliation(s)
- Beata Kolesinska
- Institute of Organic Chemistry, Technical University of Łodz, Zeromskiego 116, PL-90-924 Łodz (phone: +48-42-631-3149).
| | - Klaus Eyer
- Laboratorium für Organische Chemie, Departement Chemie und Angewandte Biowissenschaften, ETH-Zürich, Hönggerberg HCI, Vladimir-Prelog-Weg 3, CH-8093 Zürich, (phone: +41-44-632-2990; fax: +41-44-632-114).,École Supérieure de Physique et de Chimie Industrielle de la Ville de Paris, 10 Rue de Vauquelin, FR-75005 Paris
| | - Tom Robinson
- Laboratorium für Organische Chemie, Departement Chemie und Angewandte Biowissenschaften, ETH-Zürich, Hönggerberg HCI, Vladimir-Prelog-Weg 3, CH-8093 Zürich, (phone: +41-44-632-2990; fax: +41-44-632-114).,Max Planck Institute of Colloids and Interfaces, Department of Theory and Bio-Systems, Am Mühlenberg 1, DE-14476 Potsdam-Golm
| | - Petra S Dittrich
- Laboratorium für Organische Chemie, Departement Chemie und Angewandte Biowissenschaften, ETH-Zürich, Hönggerberg HCI, Vladimir-Prelog-Weg 3, CH-8093 Zürich, (phone: +41-44-632-2990; fax: +41-44-632-114).
| | - Albert K Beck
- Laboratorium für Organische Chemie, Departement Chemie und Angewandte Biowissenschaften, ETH-Zürich, Hönggerberg HCI, Vladimir-Prelog-Weg 3, CH-8093 Zürich, (phone: +41-44-632-2990; fax: +41-44-632-114)
| | - Dieter Seebach
- Laboratorium für Organische Chemie, Departement Chemie und Angewandte Biowissenschaften, ETH-Zürich, Hönggerberg HCI, Vladimir-Prelog-Weg 3, CH-8093 Zürich, (phone: +41-44-632-2990; fax: +41-44-632-114).
| | - Peter Walde
- Institut für Polymere, Departement Materialwissenschaft, ETH-Zürich, Hönggerberg HCI, Vladimir-Prelog-Weg 5, CH-8093 Zürich, (phone: +41-44-632-0473; fax: +41-44-632-126).
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8
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Purkayastha N, Capone S, Beck AK, Seebach D, Leeds J, Thompson K, Moser HE. Antibacterial Activity of Enrofloxacin and Ciprofloxacin Derivatives ofβ-Octaarginine. Chem Biodivers 2015; 12:179-93. [DOI: 10.1002/cbdv.201400456] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2014] [Indexed: 11/09/2022]
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9
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Valkenier H, López Mora N, Kros A, Davis AP. Visualization and quantification of transmembrane ion transport into giant unilamellar vesicles. Angew Chem Int Ed Engl 2014; 54:2137-41. [PMID: 25556546 PMCID: PMC4506561 DOI: 10.1002/anie.201410200] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 11/21/2014] [Indexed: 12/02/2022]
Abstract
Transmembrane ion transporters (ionophores) are widely investigated as supramolecular agents with potential for biological activity. Tests are usually performed in synthetic membranes that are assembled into large unilamellar vesicles (LUVs). However transport must be followed through bulk properties of the vesicle suspension, because LUVs are too small for individual study. An alternative approach is described whereby ion transport can be revealed and quantified through direct observation. The method employs giant unilamellar vesicles (GUVs), which are 20–60 μm in diameter and readily imaged by light microscopy. This allows characterization of individual GUVs containing transporter molecules, followed by studies of transport through fluorescence emission from encapsulated indicators. The method provides new levels of certainty and relevance, given that the GUVs are similar in size to living cells. It has been demonstrated using a highly active anion carrier, and should aid the development of compounds for treating channelopathies such as cystic fibrosis.
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Affiliation(s)
- Hennie Valkenier
- School of Chemistry, University of Bristol, Cantock's Close, Bristol BS8 1TS (UK)
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10
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Valkenier H, López Mora N, Kros A, Davis AP. Visualization and Quantification of Transmembrane Ion Transport into Giant Unilamellar Vesicles. Angew Chem Int Ed Engl 2014. [DOI: 10.1002/ange.201410200] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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11
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Gasparini G, Bang EK, Molinard G, Tulumello DV, Ward S, Kelley SO, Roux A, Sakai N, Matile S. Cellular Uptake of Substrate-Initiated Cell-Penetrating Poly(disulfide)s. J Am Chem Soc 2014; 136:6069-74. [DOI: 10.1021/ja501581b] [Citation(s) in RCA: 178] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Giulio Gasparini
- School
of Chemistry and Biochemistry, National Centre of Competence in Research
(NCCR) Chemical Biology, University of Geneva, Geneva 1211, Switzerland
| | - Eun-Kyoung Bang
- School
of Chemistry and Biochemistry, National Centre of Competence in Research
(NCCR) Chemical Biology, University of Geneva, Geneva 1211, Switzerland
| | - Guillaume Molinard
- School
of Chemistry and Biochemistry, National Centre of Competence in Research
(NCCR) Chemical Biology, University of Geneva, Geneva 1211, Switzerland
| | - David V. Tulumello
- School
of Chemistry and Biochemistry, National Centre of Competence in Research
(NCCR) Chemical Biology, University of Geneva, Geneva 1211, Switzerland
- Department
of Pharmaceutical Sciences and Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Sandra Ward
- School
of Chemistry and Biochemistry, National Centre of Competence in Research
(NCCR) Chemical Biology, University of Geneva, Geneva 1211, Switzerland
| | - Shana O. Kelley
- Department
of Pharmaceutical Sciences and Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 3M2, Canada
| | - Aurelien Roux
- School
of Chemistry and Biochemistry, National Centre of Competence in Research
(NCCR) Chemical Biology, University of Geneva, Geneva 1211, Switzerland
| | - Naomi Sakai
- School
of Chemistry and Biochemistry, National Centre of Competence in Research
(NCCR) Chemical Biology, University of Geneva, Geneva 1211, Switzerland
| | - Stefan Matile
- School
of Chemistry and Biochemistry, National Centre of Competence in Research
(NCCR) Chemical Biology, University of Geneva, Geneva 1211, Switzerland
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12
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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.
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Affiliation(s)
- Qasim Saleem
- Department of Chemistry and ‡Department of Physics, University of Toronto , Toronto, Ontario, Canada
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13
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A liposomal fluorescence assay to study permeation kinetics of drug-like weak bases across the lipid bilayer. J Control Release 2013; 173:102-9. [PMID: 24211703 DOI: 10.1016/j.jconrel.2013.10.037] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2013] [Revised: 10/26/2013] [Accepted: 10/29/2013] [Indexed: 02/04/2023]
Abstract
Lipid bilayer permeation is considered the major route for in vivo barrier passage of drugs. Despite this fact, no technique is currently available to measure the kinetics of permeation across a single lipid bilayer of structurally unrelated drug-like solutes. We developed a liposomal fluorescence assay capable to determine permeation kinetics of basic drug-like solutes across lipid bilayers. The assay is based on the hypothesis that permeation of a weak base along a concentration gradient results in net proton release at the cis-side and net proton capture at the trans-side of the bilayer. The resulting pH changes were monitored with pH-sensitive fluorophores: Test compounds were incubated with liposomes containing a pH-sensitive fluorophore at the bilayer surfaces or in the aqueous lumen and fluorescence changes were monitored with a stopped-flow apparatus in solution or by total internal reflection fluorescence microscopy with surface-captured liposomes on a microfluidic platform. Incubation with lipophilic basic drugs resulted in the expected fluorescence changes while incubation with compounds without basic functionality or high polarity did not affect fluorescence. Kinetics of fluorescence changes followed bi-exponential functions. Logarithmic permeation coefficients (logPermapp) determined in solution and by microfluidics technology showed a good correlation (r(2)=0.94, n=7) and logPermapp increased with increasing lipophilicity. Neither diffusion in the aqueous phase nor partitioning into the bilayer was rate-limiting. PEGylation of 2% of the liposomal lipids reduced Permapp by a factor ~300. In conclusion, the presented liposomal fluorescence assay is capable to determine permeation kinetics of weak basic drug-like solutes across lipid bilayers. The method is adaptable to microfluidics technology for high-throughput measurements and can potentially be modified to work for weak acid solutes.
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14
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Calcein release behavior from liposomal bilayer; influence of physicochemical/mechanical/structural properties of lipids. Biochimie 2013; 95:2018-33. [DOI: 10.1016/j.biochi.2013.07.006] [Citation(s) in RCA: 107] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 07/08/2013] [Indexed: 11/22/2022]
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15
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Purkayastha N, Eyer K, Robinson T, Dittrich PS, Beck AK, Seebach D, Kolesinska B, Cadalbert R. Enantiomeric and Diastereoisomeric (Mixed)L/ D-Octaarginine Derivatives - A Simple Way of Modulating the Properties of Cell-Penetrating Peptides. Chem Biodivers 2013; 10:1165-84. [DOI: 10.1002/cbdv.201300180] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Indexed: 12/12/2022]
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16
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Shimanouchi T, Umakoshi H, Kuboi R. Growth behavior of giant vesicles using the electroformation method: Effect of proteins on swelling and deformation. J Colloid Interface Sci 2013; 394:269-76. [DOI: 10.1016/j.jcis.2012.11.046] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Revised: 11/24/2012] [Accepted: 11/26/2012] [Indexed: 11/27/2022]
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17
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Bang EK, Gasparini G, Molinard G, Roux A, Sakai N, Matile S. Substrate-initiated synthesis of cell-penetrating poly(disulfide)s. J Am Chem Soc 2013; 135:2088-2091. [PMID: 23363440 PMCID: PMC4601153 DOI: 10.1021/ja311961k] [Citation(s) in RCA: 155] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Lessons from surface-initiated polymerization are applied to grow cell-penetrating poly(disulfide)s directly on substrates of free choice. Reductive depolymerization after cellular uptake should then release the native substrates and minimize toxicity. In the presence of thiolated substrates, propagators containing a strained disulfide from asparagusic or, preferably, lipoic acid and a guanidinium cation polymerize into poly(disulfide)s in less than 5 min at room temperature at pH 7. Substrate-initiated polymerization of cationic poly(disulfide)s and their depolymerization with dithiothreitol causes the appearance and disappearance of transport activity in fluorogenic vesicles. The same process is further characterized by gel-permeation chromatography and fluorescence resonance energy transfer.
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Affiliation(s)
- Eun-Kyoung Bang
- School of Chemistry and Biochemistry, University of Geneva, Geneva, Switzerland
| | - Giulio Gasparini
- School of Chemistry and Biochemistry, University of Geneva, Geneva, Switzerland
| | - Guillaume Molinard
- School of Chemistry and Biochemistry, University of Geneva, Geneva, Switzerland
| | - Aurélien Roux
- School of Chemistry and Biochemistry, University of Geneva, Geneva, Switzerland
| | - Naomi Sakai
- School of Chemistry and Biochemistry, University of Geneva, Geneva, Switzerland
| | - Stefan Matile
- School of Chemistry and Biochemistry, University of Geneva, Geneva, Switzerland
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Kolesinska B, Podwysocka DJ, Rueping MA, Seebach D, Kamena F, Walde P, Sauer M, Windschiegl B, Meyer-Ács M, Vor der Brüggen M, Giehring S. Permeation through Phospholipid Bilayers, Skin-Cell Penetration, Plasma Stability, and CD Spectra ofα- andβ-Oligoproline Derivatives. Chem Biodivers 2013; 10:1-38. [DOI: 10.1002/cbdv.201200393] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Indexed: 11/06/2022]
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19
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Franzen U, Østergaard J. Physico-chemical characterization of liposomes and drug substance–liposome interactions in pharmaceutics using capillary electrophoresis and electrokinetic chromatography. J Chromatogr A 2012; 1267:32-44. [DOI: 10.1016/j.chroma.2012.07.018] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Revised: 07/02/2012] [Accepted: 07/06/2012] [Indexed: 01/19/2023]
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Kuroiwa T, Fujita R, Kobayashi I, Uemura K, Nakajima M, Sato S, Walde P, Ichikawa S. Efficient Preparation of Giant Vesicles as Biomimetic Compartment Systems with High Entrapment Yields for Biomacromolecules. Chem Biodivers 2012; 9:2453-72. [DOI: 10.1002/cbdv.201200274] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Indexed: 11/09/2022]
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21
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Montenegro J, Bang EK, Sakai N, Matile S. Synthesis of an Enlarged Library of Dynamic DNA Activators with Oxime, Disulfide and Hydrazone Bridges. Chemistry 2012; 18:10436-43. [DOI: 10.1002/chem.201200550] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Indexed: 12/18/2022]
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22
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Doval DA, Fin A, Takahashi-Umebayashi M, Riezman H, Roux A, Sakai N, Matile S. Amphiphilic dynamic NDI and PDI probes: imaging microdomains in giant unilamellar vesicles. Org Biomol Chem 2012; 10:6087-93. [DOI: 10.1039/c2ob25119a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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23
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Relationship between the mobility of phosphocholine headgroups of liposomes and the hydrophobicity at the membrane interface: A characterization with spectrophotometric measurements. Colloids Surf B Biointerfaces 2011; 88:221-30. [DOI: 10.1016/j.colsurfb.2011.06.036] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Revised: 06/21/2011] [Accepted: 06/24/2011] [Indexed: 11/23/2022]
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24
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Montenegro J, Fin A, Matile S. Comprehensive screening of octopus amphiphiles as DNA activators in lipid bilayers: implications on transport, sensing and cellular uptake. Org Biomol Chem 2011; 9:2641-7. [DOI: 10.1039/c0ob00948b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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25
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Montenegro J, Braun J, Fischer-Onaca O, Meier W, Matile S. Synthetic polyion-counterion transport systems in polymersomes and gels. Org Biomol Chem 2011; 9:6623-8. [DOI: 10.1039/c1ob05835e] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Walde P, Cosentino K, Engel H, Stano P. Giant Vesicles: Preparations and Applications. Chembiochem 2010; 11:848-65. [DOI: 10.1002/cbic.201000010] [Citation(s) in RCA: 556] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Takeuchi T, Bagnacani V, Sansone F, Matile S. Amphiphilic Counterion Activators for DNA: Stimuli-Responsive Cation Transporters and Biosensors in Bulk and Lipid Bilayer Membranes. Chembiochem 2009; 10:2793-9. [DOI: 10.1002/cbic.200900512] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Krämer S, Lombardi D, Primorac A, Thomae A, Wunderli-Allenspach H. Lipid-Bilayer Permeation of Drug-Like Compounds. Chem Biodivers 2009; 6:1900-16. [DOI: 10.1002/cbdv.200900122] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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29
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Shimanouchi T, Walde P, Gardiner J, Capone S, Seebach D, Kuboi R. Inversion of the Configuration of a Single Stereocenter in a β-Heptapeptide Leads to Drastic Changes in its Interaction with Phospholipid Bilayers. Chembiochem 2009; 10:1978-81. [DOI: 10.1002/cbic.200900175] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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30
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Shimanouchi T, Ishii H, Yoshimoto N, Umakoshi H, Kuboi R. Calcein permeation across phosphatidylcholine bilayer membrane: effects of membrane fluidity, liposome size, and immobilization. Colloids Surf B Biointerfaces 2009; 73:156-60. [PMID: 19560324 DOI: 10.1016/j.colsurfb.2009.05.014] [Citation(s) in RCA: 98] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 05/06/2009] [Accepted: 05/07/2009] [Indexed: 11/16/2022]
Abstract
The permeation of calcein across the phospholipid bilayer membrane is a key phenomenon in the detection system using liposomes as a sensor unit. The behavior of the calcein release from the liposome was analyzed by a first-order kinetic to obtain the permeability coefficient, Ps [cm/s]. The Ps value for the neutral liposome, prepared by zwitterionic 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), was found to depend on both the diameter of liposome and the temperature. The membrane fluidity of the POPC liposome, evaluated by the hydrophobic probe, 1-(4-trimethyl-aminophenyl)-6-diphenyl-1,3,5-hexatriene, was also dependent on the liposome diameter and the temperature. The Ps values for various neutral liposomes under gel phase or liquid-crystalline phase were correlated with their membrane fluidity, although some data were a little scattered, possibly due to the lamellarity. It is therefore considered that the membrane fluidity dominates the permeability of calcein across the neutral phospholipid membrane. Based on the above results, the Ps value for liposomes immobilized on the solid surface is discussed.
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Affiliation(s)
- Toshinori Shimanouchi
- Division of Chemical Engineering, Graduate School of Engineering Science, Osaka University, 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan
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Shimanouchi T, Umakoshi H, Kuboi R. Kinetic study on giant vesicle formation with electroformation method. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:4835-4840. [PMID: 19334719 DOI: 10.1021/la8040488] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Giant vesicles (GVs) composed of zwitterionic phospholipids were prepared by the electroformation method. The growth behavior of GVs was quantitatively analyzed as a first-order kinetics of the radius of GVs to obtain the apparent growth rate constant k(Gr). On the basis of the dependence of the k(Gr) value on the preparation temperature and the lipid composition of GVs, the membrane fluidity of vesicle membranes was found to be dominant in the growth behavior of GVs. The comparison of the k(Gr) values with the membrane fluidity for GVs suggested the validity of the model that the swelling of the lipid membrane could induce the growth of GVs.
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Affiliation(s)
- Toshinori Shimanouchi
- Department of Chemical Science and Engineering, Graduate School of Engineering Science, Osaka University 1-3 Machikaneyama-cho, Toyonaka, Osaka 560-8531, Japan
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Butterfield S, Miyatake T, Matile S. Amplifier-Mediated Activation of Cell-Penetrating Peptides with Steroids: Multifunctional Anion Transporters for Fluorogenic Cholesterol Sensing in Eggs and Blood. Angew Chem Int Ed Engl 2009. [DOI: 10.1002/ange.200804422] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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33
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Butterfield S, Miyatake T, Matile S. Amplifier-Mediated Activation of Cell-Penetrating Peptides with Steroids: Multifunctional Anion Transporters for Fluorogenic Cholesterol Sensing in Eggs and Blood. Angew Chem Int Ed Engl 2009; 48:325-8. [DOI: 10.1002/anie.200804422] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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34
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Butterfield SM, Hennig A, Matile S. Colorful methods to detect ion channels and pores: intravesicular chromogenic probes that respond to pH, pM and covalent capture. Org Biomol Chem 2009; 7:1784-92. [DOI: 10.1039/b900130a] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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35
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Takeuchi T, Sakai N, Matile S. Counterion-activated polyions as soft sensing systems in lipid bilayer membranes: from cell-penetrating peptides to DNA. Faraday Discuss 2009; 143:187-203; discussion 265-75. [DOI: 10.1039/b900133f] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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36
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Abstract
For more than a decade now, a search for answers to the following two questions has taken us on a new and exciting journey into the world of beta- and gamma-peptides: What happens if the oxygen atoms in a 3i-helix of a polymeric chain composed of (R)-3-hydroxybutanoic acid are replaced by NH units? What happens if one or two CH2 groups are introduced into each amino acid building block in the chain of a peptide or protein, thereby providing homologues of the proteinogenic alpha-amino acids? Our journey has repeatedly thrown up surprises, continually expanding the potential of these classes of compound and deepening our understanding of the structures, properties, and multifaceted functions of the natural "models" to which they are related. Beta-peptides differ from their natural counterparts, the alpha-peptides, by having CH2 groups inserted into every amino acid residue, either between the C=O groups and the alpha-carbon atoms (beta(3)) or between the alpha-carbon and nitrogen atoms (beta(2)). The synthesis of these homologated proteinogenic amino acids and their assembly into beta-peptides can be performed using known methods. Despite the increased number of possible conformers, the beta-peptides form secondary structures (helices, turns, sheets) even when the chain lengths are as short as four residues. Furthermore, they are stable toward degrading and metabolizing enzymes in living organisms. Linear, helical, and hairpin-type structures of beta-peptides can now be designed in such a way that they resemble the characteristic and activity-related structural features ("epitopes") of corresponding natural peptides or protein sections. This Account presents examples of beta-peptidic compounds binding, as agonists or antagonists (inhibitors), to (i) major histocompatibility complex (MHC) proteins (immune response), (ii) the lipid-transport protein SR-B1 (cholesterol uptake from the small intestine), (iii) the core (1-60) of interleukin-8 (inflammation), (iv) the oncoprotein RDM2, (v) the HIVgp41 fusion protein, (vi) G-protein-coupled somatostatin hsst receptors, (vii) the TNF immune response receptor CD40 (apoptosis), and (viii) DNA. Short-chain beta-peptides may be orally bioavailable and excreted from the body of mammals; long-chain beta-peptides may require intravenous administration but will have longer half-lives of clearance. It has been said that an interesting field of research distinguishes itself in that the results always throw up new questions; in this sense, the structural and biological investigation of beta-peptides has been a gold mine. We expect that these peptidic peptidomimetics will play an increasing role in biomedical research and drug development in the near future.
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Affiliation(s)
- Dieter Seebach
- Laboratorium für Organische Chemie, Departement Chemie und Angewandte Biowissenschaften, ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
| | - James Gardiner
- Laboratorium für Organische Chemie, Departement Chemie und Angewandte Biowissenschaften, ETH Zürich, Wolfgang-Pauli-Strasse 10, CH-8093 Zürich, Switzerland
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Wu YD, Han W, Wang DP, Gao Y, Zhao YL. Theoretical analysis of secondary structures of beta-peptides. Acc Chem Res 2008; 41:1418-27. [PMID: 18828608 DOI: 10.1021/ar800070b] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Unlike alpha-amino acids, peptides formed from beta-amino acids (beta-peptides) display stability toward enzymatic degradation and may form turns and helices with as few as four residues. Because both the C alpha and C beta of the beta-amino acid may bear substituents, a large number of beta-amino acids can be synthesized. Beta-peptides form various well-defined secondary structures, including 14-helix, 12-helix, 10/12-helix, 10-helix, 8-helix, turn structures, sheets, and hairpins. For all of these reasons, beta-amino acids have been increasingly used as building blocks for molecular design and pharmaceutical applications. To explain the conformational features of beta-peptides, several quantum mechanics and molecular dynamics studies that rationalize the observed conformational features have been reported. However, a systematic account that unifies various factors critical to the conformational features is still lacking. In this Account, we present a detailed analysis of the conformational features of various beta-peptides. We start by studying the basic local conformational features of beta-peptides using di- and tripeptide models. Then, various secondary structures of unsubstituted beta-peptides with differing numbers of residues are investigated using a repeating unit approach to derive the intrinsic backbone conformational features. We find that the 10/12-helix is intrinsically most stable for the beta-peptide backbone. The 14-helix, 12-helix, and 10-helix structures have similar stabilities for beta-peptide backbones of four to six residues. The substituent effects on the stabilities of beta-peptide secondary structures are then analyzed. Combined with the substituent effect and the intrinsic backbone preferences, all experimental observations of secondary structure formation can be understood. For example, the 10/12-helix is favored for like-beta(2)/beta(3)-peptides, unlike-beta(3)/beta(3)-peptides, and beta(3)/beta-hGly-peptides because these substitution patterns do not cause steric problems for the 10/12-helix. Beta(3)-peptides, beta(2)-peptides, and beta (2,3)-peptides favor the 14-helix because the substituents in these peptides benefit the 14-helix the most but significantly destabilize the 10/12-helix. Because the 10/12-helix is intrinsically favored and has two favorable positions in each residue for substituents, many more hybrid beta-peptides are predicted to exist in this secondary structure, which suggests the need for further experiments. These results are valuable for determining the best use of these building blocks in the design of well-structured molecules with desirable chemical functions.
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Affiliation(s)
- Yun-Dong Wu
- Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Wei Han
- Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - De-Ping Wang
- Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yi Gao
- Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yi-Lei Zhao
- Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Kowloon, Hong Kong, China
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Kapitán J, Zhu F, Hecht L, Gardiner J, Seebach D, Barron L. Solution Structures of β Peptides from Raman Optical Activity. Angew Chem Int Ed Engl 2008; 47:6392-4. [DOI: 10.1002/anie.200801111] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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39
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Kapitán J, Zhu F, Hecht L, Gardiner J, Seebach D, Barron L. Solution Structures of β Peptides from Raman Optical Activity. Angew Chem Int Ed Engl 2008. [DOI: 10.1002/ange.200801111] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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40
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Hennig A, Gabriel GJ, Tew GN, Matile S. Stimuli-responsive polyguanidino-oxanorbornene membrane transporters as multicomponent sensors in complex matrices. J Am Chem Soc 2008; 130:10338-44. [PMID: 18624407 PMCID: PMC2646665 DOI: 10.1021/ja802587j] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2008] [Indexed: 11/29/2022]
Abstract
We introduce guanidinium-containing synthetic polymers based on polyguanidino-oxanorbornenes (PGONs) as anion transporters in lipid bilayers that can be activated and inactivated by chemical stimulation. According to fluorogenic anion export experiments with vesicles, PGON transporters are most active in neutral bilayers near their phase transition, with EC50's in the nanomolar range. Six times higher effective transporter concentrations were measured with aminonaphthalene-1,3,6-trisulfonate than with 5(6)-carboxyfluorescein, demonstrating the importance of anion binding for transport and excluding nonspecific efflux. Negative surface potentials efficiently annihilate transport activity, while inside-negative membrane potentials slightly increase it. These trends demonstrate the functional importance of counterions to hinder the binding of hydrophilic counterions and to minimize the global positive charge of the transporter-counterion complexes. Strong, nonlinear increases in activity with polymer length reveal a significant polymer effect. Overall, the characteristics of PGONs do not match those of similar systems (for example, polyarginine) and hint toward an interesting mode of action, clearly different from nonspecific leakage caused by detergents. The activity of PGONs increases in the presence of amphiphilic anions such as pyrenebutyrate (EC50 = 70 microM), while several other amphiphilic anions tested were inactive. PGONs are efficiently inactivated by numerous hydrophilic anions including ATP (IC 50 = 150 microM), ADP (IC50 = 460 microM), heparin (IC50 = 1.0 microM), phytate (IC50 = 0.4 microM), and CB hydrazide (IC50 = 26 microM). The compatibility of this broad responsiveness with multicomponent sensing in complex matrices is discussed and illustrated with lactate sensing in sour milk. The PGON lactate sensor operates together with lactate oxidase as a specific signal generator and CB hydrazide as an amplifier for covalent capture of the pyruvate product as CB hydrazone (IC50 = 1.5 microM).
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Affiliation(s)
- Andreas Hennig
- Department of Organic Chemistry, University of Geneva, Geneva, Switzerland
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41
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Herce HD, Garcia AE. Cell penetrating peptides: how do they do it? J Biol Phys 2008; 33:345-56. [PMID: 19669523 DOI: 10.1007/s10867-008-9074-3] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Accepted: 04/07/2008] [Indexed: 12/23/2022] Open
Abstract
Cell penetrating peptides consist of short sequences of amino acids containing a large net positive charge that are able to penetrate almost any cell, carrying with them relatively large cargoes such as proteins, oligonucleotides, and drugs. During the 10 years since their discovery, the question of how they manage to translocate across the membrane has remained unanswered. The main discussion has been centered on whether they follow an energy-independent or an energy-dependent pathway. Recently, we have discovered the possibility of an energy-independent pathway that challenges fundamental concepts associated with protein-membrane interactions (Herce and Garcia, PNAS, 104: 20805 (2007) [1]). It involves the translocation of charged residues across the hydrophobic core of the membrane and the passive diffusion of these highly charged peptides across the membrane through the formation of aqueous toroidal pores. The aim of this review is to discuss the details of the mechanism and interpret some experimental results consistent with this view.
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Affiliation(s)
- Henry D Herce
- Department of Physics and Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY 12180, USA.
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Missner A, Horner A, Pohl P. Cholesterol's decoupling effect on membrane partitioning and permeability revisited: is there anything beyond Fick's law of diffusion? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:2154-6. [PMID: 18510944 DOI: 10.1016/j.bbamem.2008.05.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2008] [Revised: 04/10/2008] [Accepted: 05/02/2008] [Indexed: 01/04/2023]
Abstract
In general, Fick's law of diffusion describes membrane permeation of hydrophobic or amphiphilic molecules. In contrast to this, Thomae et al. recently identified the volume ratio between barrier and aqueous compartments as important additional determinants of membrane permeability (Pm) [A.V. Thomae, T. Koch, C. Panse, H. Wunderli-Allenspach, and S.D. Kramer, Comparing the lipid membrane affinity and permeation of drug-like acids: the intriguing effects of cholesterol and charged lipids, Pharm. Res. 24 (2007) 1457-1472.]. This new theory was supported by the striking observation that low concentrations of cholesterol increased Pm of salicylic acid. As Fick's law is of fundamental importance to all membrane transport processes, we reinvestigated this phenomenon. We measured the electrophoretic mobility of vesicles and used electrochemical scanning microscopy to study the adsorption of the SA anion to lipid vesicular bilayers and SA transport through planar lipid bilayers, respectively. As predicted by Fick's law, Pm of SA decreased continuously with increasing cholesterol content. Thomae et al. made the contrasting artifactual observation because their kinetic approach lacked the required time resolution and led to an underestimation of Pm by five orders of magnitude. We conclude that there is nothing beyond Fick's law of diffusion. It is still valid.
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Affiliation(s)
- Andreas Missner
- Institut für Biophysik, Johannes Kepler Universität, Linz, Austria
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