1
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Pourmasoumi F, Hengoju S, Beck K, Stephan P, Klopfleisch L, Hoernke M, Rosenbaum MA, Kries H. Analysing Megasynthetase Mutants at High Throughput Using Droplet Microfluidics. Chembiochem 2023; 24:e202300680. [PMID: 37804133 DOI: 10.1002/cbic.202300680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 10/05/2023] [Indexed: 10/08/2023]
Abstract
Nonribosomal peptide synthetases (NRPSs) are giant enzymatic assembly lines that deliver many pharmaceutically valuable natural products, including antibiotics. As the search for new antibiotics motivates attempts to redesign nonribosomal metabolic pathways, more robust and rapid sorting and screening platforms are needed. Here, we establish a microfluidic platform that reliably detects production of the model nonribosomal peptide gramicidin S. The detection is based on calcein-filled sensor liposomes yielding increased fluorescence upon permeabilization. From a library of NRPS mutants, the sorting platform enriches the gramicidin S producer 14.5-fold, decreases internal stop codons 250-fold, and generates enrichment factors correlating with enzyme activity. Screening for NRPS activity with a reliable non-binary sensor will enable more sophisticated structure-activity studies and new engineering applications in the future.
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Affiliation(s)
- Farzaneh Pourmasoumi
- Junior Research Group Biosynthetic Design of Natural Products, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Sundar Hengoju
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Katharina Beck
- Faculty of Chemistry and Pharmacy, Albert-Ludwigs-Universität, Hermann-Herder-Str. 9, 79104, Freiburg i. Br., Germany
| | - Philipp Stephan
- Junior Research Group Biosynthetic Design of Natural Products, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Lukas Klopfleisch
- Junior Research Group Biosynthetic Design of Natural Products, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
| | - Maria Hoernke
- Faculty of Chemistry and Pharmacy, Albert-Ludwigs-Universität, Hermann-Herder-Str. 9, 79104, Freiburg i. Br., Germany
- Faculty of Chemistry, Martin-Luther-Universität, Von-Danckelmann-Platz 4, 06108, Halle (S.), Germany
| | - Miriam A Rosenbaum
- Bio Pilot Plant, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
- Faculty of Biological Sciences, Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Hajo Kries
- Junior Research Group Biosynthetic Design of Natural Products, Leibniz Institute for Natural Product Research and Infection Biology (HKI), Beutenbergstr. 11a, 07745, Jena, Germany
- Department of Chemistry, University of Bayreuth, Universitätsstrasse 30, 95440, Bayreuth, Germany
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2
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Nimmrich A, Panman MR, Berntsson O, Biasin E, Niebling S, Petersson J, Hoernke M, Björling A, Gustavsson E, van Driel TB, Dohn AO, Laursen M, Zederkof DB, Tono K, Katayama T, Owada S, Nielsen MM, Davidsson J, Uhlig J, Hub JS, Haldrup K, Westenhoff S. Solvent-Dependent Structural Dynamics in the Ultrafast Photodissociation Reaction of Triiodide Observed with Time-Resolved X-ray Solution Scattering. J Am Chem Soc 2023. [PMID: 37163700 PMCID: PMC10375522 DOI: 10.1021/jacs.3c00484] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
Resolving the structural dynamics of bond breaking, bond formation, and solvation is required for a deeper understanding of solution-phase chemical reactions. In this work, we investigate the photodissociation of triiodide in four solvents using femtosecond time-resolved X-ray solution scattering following 400 nm photoexcitation. Structural analysis of the scattering data resolves the solvent-dependent structural evolution during the bond cleavage, internal rearrangements, solvent-cage escape, and bond reformation in real time. The nature and structure of the reaction intermediates during the recombination are determined, elucidating the full mechanism of photodissociation and recombination on ultrafast time scales. We resolve the structure of the precursor state for recombination as a geminate pair. Further, we determine the size of the solvent cages from the refined structures of the radical pair. The observed structural dynamics present a comprehensive picture of the solvent influence on structure and dynamics of dissociation reactions.
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Affiliation(s)
- Amke Nimmrich
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Matthijs R Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Oskar Berntsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Elisa Biasin
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Stephan Niebling
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Jonas Petersson
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Maria Hoernke
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Alexander Björling
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Emil Gustavsson
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
| | - Tim B van Driel
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Asmus O Dohn
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
- Faculty of Physical Sciences, University of Iceland, VR-III, 107 Reykjavík, Iceland
| | - Mads Laursen
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Diana B Zederkof
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Kensuke Tono
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Tetsuo Katayama
- Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - Shigeki Owada
- RIKEN SPring-8 Center, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Martin M Nielsen
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Jan Davidsson
- Department of Chemistry, Ångström Laboratory, Uppsala University, Box 523, 75120 Uppsala, Sweden
| | - Jens Uhlig
- Department of Chemical Physics, Lund University, Box 124, 22100 Lund, Sweden
| | - Jochen S Hub
- Georg-August-Universität Göttingen, Institute for Microbiology and Genetics, Justus-von-Liebig-Weg 11, 37077 Göttingen, Germany
| | - Kristoffer Haldrup
- Department of Physics, Technical University of Denmark, 2800 Lyngby, Denmark
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, 40530 Gothenburg, Sweden
- Department of Chemical Physics, Lund University, Box 124, 22100 Lund, Sweden
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3
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Beck K, Nandy J, Hoernke M. Membrane permeabilization can be crucially biased by a fusogenic lipid composition - leaky fusion caused by antimicrobial peptides in model membranes. Soft Matter 2023; 19:2919-2931. [PMID: 37010846 DOI: 10.1039/d2sm01691e] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Induced membrane permeabilization or leakage is often taken as an indication for activity of membrane-active molecules, such as antimicrobial peptides (AMPs). The exact leakage mechanism is often unknown, but important, because certain mechanisms might actually contribute to microbial killing, while others are unselective, or potentially irrelevant in an in vivo situation. Using an antimicrobial example peptide (cR3W3), we illustrate one of the potentially misleading leakage mechanisms: leaky fusion, where leakage is coupled to membrane fusion. Like many others, we examine peptide-induced leakage in model vesicles consisting of binary mixtures of anionic and zwitterionic phospholipids. In fact, phosphatidylglycerol and phosphatidylethanolamine (PG/PE) are supposed to reflect bacterial membranes, but exhibit a high propensity for vesicle aggregation and fusion. We describe the implications of this vesicle fusion and aggregation for the reliability of model studies. The ambiguous role of the relatively fusogenic PE-lipids becomes clear as leakage decreases significantly when aggregation and fusion are prevented by sterical shielding. Furthermore, the mechanism of leakage changes if PE is exchanged for phosphatidylcholine (PC). We thus point out that the lipid composition of model membranes can be biased towards leaky fusion. This can lead to discrepancies between model studies and activity in true microbes, because leaky fusion is likely prevented by bacterial peptidoglycan layers. In conclusion, choosing the model membrane might implicate the type of effect (here leakage mechanism) that is observed. In the worst case, as with leaky fusion of PG/PE vesicles, this is not directly relevant for the intended antimicrobial application.
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Affiliation(s)
- Katharina Beck
- Chemistry and Pharmacy, Albert-Ludwigs-Universität, Freiburg i. Br., Germany.
| | - Janina Nandy
- Chemistry and Pharmacy, Albert-Ludwigs-Universität, Freiburg i. Br., Germany.
| | - Maria Hoernke
- Chemistry and Pharmacy, Albert-Ludwigs-Universität, Freiburg i. Br., Germany.
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4
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Shi S, Fan H, Hoernke M. Leaky membrane fusion: an ambivalent effect induced by antimicrobial polycations. Nanoscale Adv 2022; 4:5109-5122. [PMID: 36504745 PMCID: PMC9680940 DOI: 10.1039/d2na00464j] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 10/24/2022] [Indexed: 05/28/2023]
Abstract
Both antimicrobial peptides and their synthetic mimics are potential alternatives to classical antibiotics. They can induce several membrane perturbations including permeabilization. Especially in model studies, aggregation of vesicles by such polycations is often reported. Here, we show that unintended vesicle aggregation or indeed fusion can cause apparent leakage in model studies that is not possible in most microbes, thus potentially leading to misinterpretations. The interactions of a highly charged and highly selective membrane-active polycation with negatively charged phosphatidylethanolamine/phosphatidylglycerol (PE/PG) vesicles are studied by a combination of biophysical methods. At low polycation concentrations, apparent vesicle aggregation was found to involve exchange of lipids. Upon neutralization of the negatively charged vesicles by the polycation, full fusion and leakage occurred and leaky fusion is suspected. To elucidate the interplay of leakage and fusion, we prevented membrane contacts by decorating the vesicles with PEG-chains. This inhibited fusion and also leakage activity. Leaky fusion is further corroborated by increased leakage with increasing likeliness of vesicle-vesicle contacts. Because of its similar appearance to other leakage mechanisms, leaky fusion is difficult to identify and might be overlooked and more common amongst polycationic membrane-active compounds. Regarding biological activity, leaky fusion needs to be carefully distinguished from other membrane permeabilization mechanisms, as it may be less relevant to bacteria, but potentially relevant for fungi. Furthermore, leaky fusion is an interesting effect that could help in endosomal escape for drug delivery. A comprehensive step-by-step protocol for membrane permeabilization/vesicle leakage using calcein fluorescence lifetime is provided in the ESI.
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Affiliation(s)
- Shuai Shi
- Chemistry and Pharmacy, Albert-Ludwigs-Universität 79104 Freiburg i.Br. Germany
| | - Helen Fan
- Leslie Dan Faculty of Pharmacy, University of Toronto Toronto Canada
| | - Maria Hoernke
- Chemistry and Pharmacy, Albert-Ludwigs-Universität 79104 Freiburg i.Br. Germany
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5
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Hausig-Punke F, Richter F, Hoernke M, Brendel JC, Traeger A. Tracking the Endosomal Escape: A Closer Look at Calcein and Related Reporters. Macromol Biosci 2022; 22:e2200167. [PMID: 35933579 DOI: 10.1002/mabi.202200167] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 07/19/2022] [Indexed: 11/11/2022]
Abstract
Crossing the cellular membrane and delivering active pharmaceuticals or biologicals into the cytosol of cells is an essential step in the development of nanomedicines. One of the most important intracellular processes regarding the cellular uptake of biologicals is the endolysosomal pathway. Sophisticated nanocarriers have been developed overcoming a major hurdle, the endosomal entrapment, and delivering their cargo to the required site of action. In parallel, in vitro assays have been established analyzing the performance of these nanocarriers. Among them, the release of the membrane-impermeable dye calcein has become a popular and straightforward method. It is accessible for most researchers worldwide, allows for rapid conclusions about the release potential, and enables the study of release mechanisms. This review is intended to provide an overview and guidance for scientists applying the calcein release assay. It comprises a survey of several applications in the study of endosomal escape, considerations of potential pitfalls, challenges and limitations of the assay, and a brief summary of complementary methods. Based on this review, we hope to encourage further research groups to take advantage of the calcein release assay for their own purposes and help to create a database for more efficient cross-correlations between nanocarriers. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Franziska Hausig-Punke
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743, Jena, Germany.,Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany
| | - Friederike Richter
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743, Jena, Germany.,Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany
| | - Maria Hoernke
- Chemistry and Pharmacy, Albert-Ludwigs-Universität Freiburg, Hermann-Herder-Str. 9, 79104, Freiburg i.Br., Germany
| | - Johannes C Brendel
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743, Jena, Germany.,Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany
| | - Anja Traeger
- Laboratory of Organic and Macromolecular Chemistry (IOMC), Friedrich Schiller University Jena, Humboldtstrasse 10, 07743, Jena, Germany.,Jena Center for Soft Matter (JCSM), Friedrich Schiller University Jena, Philosophenweg 7, 07743, Jena, Germany
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6
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Shi S, Markl AM, Lu Z, Liu R, Hoernke M. Interplay of Fusion, Leakage, and Electrostatic Lipid Clustering: Membrane Perturbations by a Hydrophobic Antimicrobial Polycation. Langmuir 2022; 38:2379-2391. [PMID: 35148117 DOI: 10.1021/acs.langmuir.1c03445] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Membrane active compounds are able to induce various types of membrane perturbations. Natural or biomimetic candidates for antimicrobial treatment or drug delivery scenarios are mostly designed and tested for their ability to induce membrane permeabilization, also termed leakage. Furthermore, the interaction of these usually cationic amphiphiles with negatively charged vesicles often causes colloidal instability leading to vesicle aggregation or/and vesicle fusion. We show the interplay of these modes of membrane perturbation in mixed phosphatidyl glycerol (PG)/phosphatidyl ethanolamine (PE) by the statistical copolymer MM:CO comprising, both, charged and hydrophobic subunits. MM:CO is a representative of partially hydrophobic, highly active, but less selective antimicrobial polycations. Cryo-electron microscopy indicates vesicle fusion rather than vesicle aggregation upon the addition of MM:CO to negatively charged PG/PE (1:1) vesicles. In a combination of fluorescence-based leakage and fusion assays, there is support for membrane permeabilization and pronounced vesicle fusion activity as distinct effects. To this end, membrane fusion and aggregation were prevented by including lipids with polyethylene glycol attached to their head groups (PEG-lipids). The leakage activity of MM:CO is very similar in the absence and presence of PEG-lipids. Vesicle aggregation and fusion however are largely suppressed. This strongly suggests that MM:CO induces leakage by asymmetric packing stress because of hydrophobically driven interactions which could lead to leakage. As a further membrane perturbation effect, MM:CO causes lipid clustering in model vesicles. We address potential artifacts and misinterpretations of experiments characterizing leakage and fusion. Additional to the leakage activity, the pronounced fusogenic activity of the polymer and potentially of many other similar compounds likely has implications for antimicrobial activity and beyond.
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Affiliation(s)
- Shuai Shi
- Chemistry and Pharmacy, Albert-Ludwigs-Universität, 79104 Freiburg i.Br., Germany
| | - Anja Madleine Markl
- Chemistry and Pharmacy, Albert-Ludwigs-Universität, 79104 Freiburg i.Br., Germany
| | - Ziyi Lu
- State Key Laboratory of Bioreactor Engineering, Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Research Center for Biomedical Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Runhui Liu
- State Key Laboratory of Bioreactor Engineering, Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, Research Center for Biomedical Materials of Ministry of Education, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Maria Hoernke
- Chemistry and Pharmacy, Albert-Ludwigs-Universität, 79104 Freiburg i.Br., Germany
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7
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Shi S, Liu R, Hoernke M. Vesicle Aggregation and Fusion Influence Membrane Permeabilization Induced by Antimicrobial Polycations. Biophys J 2021. [DOI: 10.1016/j.bpj.2020.11.1053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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8
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Shi S, Quarta N, Zhang H, Lu Z, Hof M, Šachl R, Liu R, Hoernke M. Hidden complexity in membrane permeabilization behavior of antimicrobial polycations. Phys Chem Chem Phys 2021; 23:1475-1488. [DOI: 10.1039/d0cp05651k] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
There are diverse membrane permeabilization behaviors of antimicrobial polycations in zwitterionic or charged vesicles; different mechanisms may occur over time.
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Affiliation(s)
- Shuai Shi
- Chemistry and Pharmacy
- Albert-Ludwigs-Universität
- 79104 Freiburg i.Br
- Germany
| | - Ndjali Quarta
- Chemistry and Pharmacy
- Albert-Ludwigs-Universität
- 79104 Freiburg i.Br
- Germany
- Department of Chemistry, Biochemistry
| | - Haodong Zhang
- State Key Laboratory of Bioreactor Engineering
- Frontiers Science Center for Materiobiology and Dynamic Chemistry
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Ziyi Lu
- State Key Laboratory of Bioreactor Engineering
- Frontiers Science Center for Materiobiology and Dynamic Chemistry
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Martin Hof
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences
- 182 23 Prague
- Czech Republic
| | - Radek Šachl
- J. Heyrovský Institute of Physical Chemistry of the Czech Academy of Sciences
- 182 23 Prague
- Czech Republic
| | - Runhui Liu
- State Key Laboratory of Bioreactor Engineering
- Frontiers Science Center for Materiobiology and Dynamic Chemistry
- School of Materials Science and Engineering
- East China University of Science and Technology
- Shanghai 200237
| | - Maria Hoernke
- Chemistry and Pharmacy
- Albert-Ludwigs-Universität
- 79104 Freiburg i.Br
- Germany
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9
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Stulz A, Braun S, Shi S, Quarta N, Hoernke M. Quantified Efficiency of Membrane Leakage Events Relates to Antimicrobial Selectivity. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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10
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Shi S, Quarta N, Liu R, Hoernke M. Induced Membrane Permeabilization and Vesicle Fusion: Synthetic Antimicrobials Acting on Model Membranes. Biophys J 2020. [DOI: 10.1016/j.bpj.2019.11.2188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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11
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Stulz A, Vogt A, Saar JS, Akil L, Lienkamp K, Hoernke M. Quantified Membrane Permeabilization Indicates the Lipid Selectivity of Membrane-Active Antimicrobials. Langmuir 2019; 35:16366-16376. [PMID: 31710807 DOI: 10.1021/acs.langmuir.9b01849] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Most antimicrobial peptides (AMPs) and their synthetic mimics (SMAMPs) are thought to act by permeabilizing cell membranes. For antimicrobial therapy, selectivity for pathogens over mammalian cells is a key requirement. Understanding membrane selectivity is thus essential for designing AMPs and SMAMPs to complement classical antibiotics in the future. This study focuses on membrane permeabilization induced by SMAMPs and their selectivity for membranes with different lipid compositions. We measure release and fluorescence lifetime of a self-quenching dye in lipid vesicles. Apart from the dose-response, we quantify the strength of individual leakage events, and, employing cumulative kinetics, categorize permeabilization behavior. We propose that differing selectivities in a series of SMAMPs arise from a combination of the effect of the antimicrobial agent and the susceptibility of the membrane (with a given lipid composition) for certain types of leakage behavior. The unselective and hemolytic SMAMP is found to act mainly by the asymmetry stress mechanism, mediated by hydrophobic insertion of SMAMPs into lipid layers. The more selective SMAMPs induced leakage events occurring stochastically over several hours. Lipid intrinsic properties might additionally amplify the efficiency of leakage events. Leakage behavior changes with both the design of the SMAMP and the lipid composition of the membrane. Understanding how leakage behavior contributes to the selectivity and activity of antimicrobial agents will aid the design and screening of antimicrobials. An understanding of the underlying processes facilitates the comparison of membrane permeabilization across in vitro and in vivo assays.
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Affiliation(s)
- Anja Stulz
- Pharmaceutical Technology and Biopharmacy , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
| | - Annika Vogt
- Pharmaceutical Technology and Biopharmacy , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
- Faculty of Applied Chemistry , Reutlingen University , Reutlingen , Germany
| | - Julia Selina Saar
- Department of Microsystems Engineering (IMTEK) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
| | - Larissa Akil
- Pharmaceutical Technology and Biopharmacy , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
| | - Karen Lienkamp
- Department of Microsystems Engineering (IMTEK) and Freiburg Center for Interactive Materials and Bioinspired Technologies (FIT) , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
| | - Maria Hoernke
- Pharmaceutical Technology and Biopharmacy , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
- BIOSS Centre for Biological Signalling Studies , Albert-Ludwigs-Universität , Freiburg i.Br ., Germany
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12
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13
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Braun S, Schnur J, Stulz A, Heerklotz HH, Hoernke M. Membrane Leakage: Further Insight by Advanced Statistical Analysis of Vesicle Leakage. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.1516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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14
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Braun S, Pokorná Š, Šachl R, Hof M, Heerklotz H, Hoernke M. Biomembrane Permeabilization: Statistics of Individual Leakage Events Harmonize the Interpretation of Vesicle Leakage. ACS Nano 2018; 12:813-819. [PMID: 29244483 DOI: 10.1021/acsnano.7b08184] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The mode of action of membrane-active molecules, such as antimicrobial, anticancer, cell penetrating, and fusion peptides and their synthetic mimics, transfection agents, drug permeation enhancers, and biological signaling molecules (e.g., quorum sensing), involves either the general or local destabilization of the target membrane or the formation of defined, rather stable pores. Some effects aim at killing the cell, while others need to be limited in space and time to avoid serious damage. Biological tests reveal translocation of compounds and cell death but do not provide a detailed, mechanistic, and quantitative understanding of the modes of action and their molecular basis. Model membrane studies of membrane leakage have been used for decades to tackle this issue, but their interpretation in terms of biology has remained challenging and often quite limited. Here we compare two recent, powerful protocols to study model membrane leakage: the microscopic detection of dye influx into giant liposomes and time-correlated single photon counting experiments to characterize dye efflux from large unilamellar vesicles. A statistical treatment of both data sets does not only harmonize apparent discrepancies but also makes us aware of principal issues that have been confusing the interpretation of model membrane leakage data so far. Moreover, our study reveals a fundamental difference between nano- and microscale systems that needs to be taken into account when conclusions about microscale objects, such as cells, are drawn from nanoscale models.
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Affiliation(s)
- Stefan Braun
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg , 79104 Freiburg im Breisgau, Germany
| | - Šárka Pokorná
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic , 182 23 Prague, Czech Republic
| | - Radek Šachl
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic , 182 23 Prague, Czech Republic
| | - Martin Hof
- Department of Biophysical Chemistry, J. Heyrovský Institute of Physical Chemistry of the Academy of Sciences of the Czech Republic , 182 23 Prague, Czech Republic
| | - Heiko Heerklotz
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg , 79104 Freiburg im Breisgau, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg , 79104 Freiburg im Breisgau, Germany
- Leslie Dan Faculty of Pharmacy, University of Toronto , 144 College St., Toronto, Ontario M5S 3M2, Canada
| | - Maria Hoernke
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg , 79104 Freiburg im Breisgau, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg , 79104 Freiburg im Breisgau, Germany
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15
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Stulz A, Römer W, Lienkamp K, Heerklotz H, Hoernke M. Lipid Clustering by Antimicrobial Polymers and Lectins. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.2069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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16
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Braun S, Pokorná Š, Šachl R, Hof M, Heerklotz H, Hoernke M. GUV and LUV Leakage: How All-Or-None and Graded Leakage Scale with Vesicle Size. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.2850] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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17
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Takala H, Niebling S, Berntsson O, Björling A, Lehtivuori H, Häkkänen H, Panman M, Gustavsson E, Hoernke M, Newby G, Zontone F, Wulff M, Menzel A, Ihalainen JA, Westenhoff S. Light-induced structural changes in a monomeric bacteriophytochrome. Struct Dyn 2016; 3:054701. [PMID: 27679804 PMCID: PMC5010554 DOI: 10.1063/1.4961911] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2016] [Accepted: 08/15/2016] [Indexed: 05/11/2023]
Abstract
Phytochromes sense red light in plants and various microorganism. Light absorption causes structural changes within the protein, which alter its biochemical activity. Bacterial phytochromes are dimeric proteins, but the functional relevance of this arrangement remains unclear. Here, we use time-resolved X-ray scattering to reveal the solution structural change of a monomeric variant of the photosensory core module of the phytochrome from Deinococcus radiodurans. The data reveal two motions, a bend and a twist of the PHY domain with respect to the chromophore-binding domains. Infrared spectroscopy shows the refolding of the PHY tongue. We conclude that a monomer of the phytochrome photosensory core is sufficient to perform the light-induced structural changes. This implies that allosteric cooperation with the other monomer is not needed for structural activation. The dimeric arrangement may instead be intrinsic to the biochemical output domains of bacterial phytochromes.
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Affiliation(s)
| | - Stephan Niebling
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg 40530, Sweden
| | - Oskar Berntsson
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg 40530, Sweden
| | - Alexander Björling
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg 40530, Sweden
| | | | - Heikki Häkkänen
- Nanoscience Center, Department of Biological and Environmental Sciences, University of Jyvaskyla , Jyväskylä 40014, Finland
| | - Matthijs Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg 40530, Sweden
| | - Emil Gustavsson
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg 40530, Sweden
| | | | - Gemma Newby
- ESRF-The European Synchrotron Radiation Facility , CS40220, 38043 Grenoble Cedex 9, France
| | - Federico Zontone
- ESRF-The European Synchrotron Radiation Facility , CS40220, 38043 Grenoble Cedex 9, France
| | - Michael Wulff
- ESRF-The European Synchrotron Radiation Facility , CS40220, 38043 Grenoble Cedex 9, France
| | | | - Janne A Ihalainen
- Nanoscience Center, Department of Biological and Environmental Sciences, University of Jyvaskyla , Jyväskylä 40014, Finland
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg , Gothenburg 40530, Sweden
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18
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Björling A, Berntsson O, Lehtivuori H, Takala H, Hughes AJ, Panman M, Hoernke M, Niebling S, Henry L, Henning R, Kosheleva I, Chukharev V, Tkachenko NV, Menzel A, Newby G, Khakhulin D, Wulff M, Ihalainen JA, Westenhoff S. Structural photoactivation of a full-length bacterial phytochrome. Sci Adv 2016; 2:e1600920. [PMID: 27536728 PMCID: PMC4982709 DOI: 10.1126/sciadv.1600920] [Citation(s) in RCA: 62] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 07/13/2016] [Indexed: 05/11/2023]
Abstract
Phytochromes are light sensor proteins found in plants, bacteria, and fungi. They function by converting a photon absorption event into a conformational signal that propagates from the chromophore through the entire protein. However, the structure of the photoactivated state and the conformational changes that lead to it are not known. We report time-resolved x-ray scattering of the full-length phytochrome from Deinococcus radiodurans on micro- and millisecond time scales. We identify a twist of the histidine kinase output domains with respect to the chromophore-binding domains as the dominant change between the photoactivated and resting states. The time-resolved data further show that the structural changes up to the microsecond time scales are small and localized in the chromophore-binding domains. The global structural change occurs within a few milliseconds, coinciding with the formation of the spectroscopic meta-Rc state. Our findings establish key elements of the signaling mechanism of full-length bacterial phytochromes.
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Affiliation(s)
| | | | | | - Heikki Takala
- University of Gothenburg, 40530 Gothenburg, Sweden
- University of Jyväskylä, 40014 Jyväskylä, Finland
| | | | | | | | | | | | | | | | | | | | - Andreas Menzel
- Paul Scherrer Institut, Villigen, 5232 Villigen PSI, Switzerland
| | - Gemma Newby
- European Synchrotron Radiation Facility, 38000 Grenoble, France
| | | | - Michael Wulff
- European Synchrotron Radiation Facility, 38000 Grenoble, France
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19
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Hoernke M, Larsson E, Mohan J, Blomberg J, Westenhoff S, Lundmark R, Schwieger C. Structural Mechanism in a Membrane Remodelling ATP-ASE. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.3090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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20
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Björling A, Berntsson O, Takala H, Gallagher KD, Patel H, Gustavsson E, St Peter R, Duong P, Nugent A, Zhang F, Berntsen P, Appio R, Rajkovic I, Lehtivuori H, Panman MR, Hoernke M, Niebling S, Harimoorthy R, Lamparter T, Stojković EA, Ihalainen JA, Westenhoff S. Ubiquitous Structural Signaling in Bacterial Phytochromes. J Phys Chem Lett 2015; 6:3379-83. [PMID: 26275765 DOI: 10.1021/acs.jpclett.5b01629] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The phytochrome family of light-switchable proteins has long been studied by biochemical, spectroscopic and crystallographic means, while a direct probe for global conformational signal propagation has been lacking. Using solution X-ray scattering, we find that the photosensory cores of several bacterial phytochromes undergo similar large-scale structural changes upon red-light excitation. The data establish that phytochromes with ordinary and inverted photocycles share a structural signaling mechanism and that a particular conserved histidine, previously proposed to be involved in signal propagation, in fact tunes photoresponse.
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Affiliation(s)
- Alexander Björling
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Oskar Berntsson
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Heikki Takala
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä , 40014 Jyväskylä, Finland
| | - Kevin D Gallagher
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Hardik Patel
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Emil Gustavsson
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Rachael St Peter
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Phu Duong
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Angela Nugent
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Fan Zhang
- Botanical Institute, Karlsruhe Institute of Technology KIT , Kaiserstr. 2, 76131 Karlsruhe, Germany
| | - Peter Berntsen
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
- Centre for Advanced Molecular Imaging, La Trobe Institute for Molecular Science, La Trobe University , Melbourne, Victoria 3086, Australia
| | - Roberto Appio
- MAX IV Laboratory, Lund University , P.O. Box 118, Lund SE-221 00, Sweden
| | - Ivan Rajkovic
- Paul Scherrer Institut , 5232 Villigen PSI, Switzerland
| | - Heli Lehtivuori
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä , 40014 Jyväskylä, Finland
| | - Matthijs R Panman
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Maria Hoernke
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Stephan Niebling
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Rajiv Harimoorthy
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
| | - Tilman Lamparter
- Botanical Institute, Karlsruhe Institute of Technology KIT , Kaiserstr. 2, 76131 Karlsruhe, Germany
| | - Emina A Stojković
- Department of Biology, Northeastern Illinois University , 5500 North St. Louis Avenue, Chicago, Illinois 60625, United States
| | - Janne A Ihalainen
- Nanoscience Center, Department of Biological and Environmental Science, University of Jyväskylä , 40014 Jyväskylä, Finland
| | - Sebastian Westenhoff
- Department of Chemistry and Molecular Biology, University of Gothenburg , Box 462, 40530 Gothenburg, Sweden
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21
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Hoernke M, Falenski JA, Schwieger C, Koksch B, Brezesinski G. Triggers for β-sheet formation at the hydrophobic-hydrophilic interface: high concentration, in-plane orientational order, and metal ion complexation. Langmuir 2011; 27:14218-14231. [PMID: 22011020 DOI: 10.1021/la203016z] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Amyloid formation plays a causative role in neurodegenerative diseases such as Alzheimer's disease or Parkinson's disease. Soluble peptides form β-sheets that subsequently rearrange into fibrils and deposit as amyloid plaques. Many parameters trigger and influence the onset of the β-sheet formation. Early stages are recently discussed to be cell-toxic. Aiming at understanding various triggers such as interactions with hydrophobic-hydrophilic interfaces and metal ion complexation and their interplay, we investigated a set of model peptides at the air-water interface. We are using a general approach to a variety of diseases such as Alzheimer's disease, Parkinson's disease, and type II diabetes that are connected to amyloid formation. Surface sensitive techniques combined with film balance measurements have been used to assess the conformation of the peptides and their orientation at the air-water interface (IR reflection-absorption spectroscopy). Additionally, the structures of the peptide layers were characterized by grazing incidence X-ray diffraction and X-ray reflectivity. The peptides adsorb to the air-water interface and immediately adopt an α-helical conformation. This helical intermediate transforms into β-sheets upon further triggering. The factors that result in β-sheet formation are dependent on the peptide sequence. In general, the interface has the strongest effect on peptide conformation compared to high concentrations or metal ions. Metal ions are able to prevent aggregation in bulk but not at the interface. At the interface, metal ion complexation has only minor effects on the peptide secondary structure, influencing the in-plane structure that is formed in two dimensions. At the air-water interface, increased concentrations or a parallel arrangement of the α-helical intermediates are the most effective triggers. This study reveals the role of various triggers for β-sheet formation and their complex interplay. Our main finding is that the hydrophobic-hydrophilic interface largely governs the conformation of peptides. Therefore, the present study implies that special care is needed when interpreting data that may be affected by different amounts or types of interfaces during experimentation.
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Affiliation(s)
- Maria Hoernke
- Department of Interfaces, Max-Planck-Institute of Colloids and Interfaces, Potsdam, Germany
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22
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Hoernke M, Koksch B, Brezesinski G. Amyloidogenic peptides at hydrophobic-hydrophilic interfaces: coordination affinities and the chelate effect dictate the competitive binding of Cu2+ and Zn2+. Chemphyschem 2011; 12:2225-9. [PMID: 21751332 DOI: 10.1002/cphc.201100215] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Indexed: 11/10/2022]
Affiliation(s)
- Maria Hoernke
- Department of Interfaces, Max Planck Institute of Colloids and Interfaces, Research Campus Golm, Potsdam, Germany.
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Erhardt A, Hoernke M, Heinzel-Pleines U, Sagir A, Göbel T, Häussinger D. Retrospective analysis of chronic hepatitis D in a West German University Clinic over two decades: migratory pattern, prevalence and clinical outcome. Z Gastroenterol 2010; 48:813-7. [PMID: 20687016 DOI: 10.1055/s-0028-1109984] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND/AIMS Epidemiology, clinical features and long term-course of chronic hepatitis D were addressed in a non-endemic Central European area. METHODS Sixty-seven patients with chronic hepatitis D were identified among 1307 HBsAg carriers at the university hospital Düsseldorf during two decades (1989 - 2008) and followed for a mean of 7 +/- 6 years. Forty-one of these were treated with IFN-alfa for at least six months. RESULTS Hepatitis D prevalence increased from 4.1 to 6.2 % among HBsAg carriers during the two decades (p < 0.06). Patients originating from the former Soviet Union (32.1 vs. 46.2 %) and Africa (0 vs. 17.9 %) became more frequent whereas the prevalence of patients from Southern Europe declined (46.5 vs.17.9 % p < 0.03). The time span between the diagnosis of hepatitis B and D was 4.8 +/- 7 years (p < 0.0001). A sustained virological response to interferon-alfa was achieved in 19.5 % of the patients. The yearly incidence rates for death, HCC and complications were 3.2 %, 2.7 % and 8 % among patients with liver cirrhosis. Estimated survival and complication-free survival during 12 years were 72 % and 45 % in cirrhotic compared to 100 % in non-cirrhotic patients (p < 0.008 and p < 0.0001, respectively). CONCLUSION Hepatitis D in western Germany appears to be on the increase and has a migration background that should be considered in clinical practice. Clinical outcome and response to IFN are as poor as in endemic regions, indicating the need to improve early diagnosis.
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Affiliation(s)
- A Erhardt
- Klinik für Gastroenterologie, Hepatologie und Infektiologie, Universitätsklinikum der Heinrich-Heine-Universität Düsseldorf.
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24
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Hanneken S, Kuerten V, Hoernke M, Neumann NJ. Metastatic colon cancer triggering an acute attack of variegate porphyria. Int J Colorectal Dis 2009; 24:127-8. [PMID: 18665372 DOI: 10.1007/s00384-008-0537-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/03/2008] [Indexed: 02/04/2023]
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