1
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Piao Y, Himbert S, Li Z, Liu J, Zhao Z, Yu H, Liu S, Shao S, Fefer M, Rheinstädter MC, Shen Y. Alkylated EDTA potentiates antibacterial photodynamic activity of protoporphyrin. J Nanobiotechnology 2024; 22:161. [PMID: 38589895 PMCID: PMC11003131 DOI: 10.1186/s12951-024-02353-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/20/2024] [Indexed: 04/10/2024] Open
Abstract
Antibiotic resistance has garnered significant attention due to the scarcity of new antibiotics in development. Protoporphyrin IX (PpIX)-mediated photodynamic therapy shows promise as a novel antibacterial strategy, serving as an alternative to antibiotics. However, the poor solubility of PpIX and its tendency to aggregate greatly hinder its photodynamic efficacy. In this study, we demonstrate that alkylated EDTA derivatives (aEDTA), particularly C14-EDTA, can enhance the solubility of PpIX by facilitating its dispersion in aqueous solutions. The combination of C14-EDTA and PpIX exhibits potent antibacterial activity against Staphylococcus aureus (S. aureus) when exposed to LED light irradiation. Furthermore, this combination effectively eradicates S. aureus biofilms, which are known to be strongly resistant to antibiotics, and demonstrates high therapeutic efficacy in an animal model of infected ulcers. Mechanistic studies reveal that C14-EDTA can disrupt PpIX crystallization, increase bacterial membrane permeability and sequester divalent cations, thereby improving the accumulation of PpIX in bacteria. This, in turn, enhances reactive oxygen species (ROS) production and the antibacterial photodynamic activity. Overall, this effective strategy holds great promise in combating antibiotic-resistant strains.
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Affiliation(s)
- Ying Piao
- Zhejiang Key Laboratory of Smart Biomaterials and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 3Z5, Canada.
| | - Zifan Li
- Zhejiang Key Laboratory of Smart Biomaterials and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Jun Liu
- Suncor AgroScience, Mississauga, ON, L5K 1A8, Canada
| | - Zhihao Zhao
- Zhejiang Key Laboratory of Smart Biomaterials and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Huahai Yu
- Zhejiang Key Laboratory of Smart Biomaterials and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Shuangshuang Liu
- Zhejiang Key Laboratory of Smart Biomaterials and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China
| | - Shiqun Shao
- Zhejiang Key Laboratory of Smart Biomaterials and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China.
| | - Michael Fefer
- Suncor AgroScience, Mississauga, ON, L5K 1A8, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 3Z5, Canada.
| | - Youqing Shen
- Zhejiang Key Laboratory of Smart Biomaterials and Key Laboratory of Biomass Chemical Engineering of Ministry of Education, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, 310058, China.
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2
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Bose RJ, Kessinger CW, Dhammu T, Singh T, Shealy MW, Ha K, Collandra R, Himbert S, Garcia FJ, Oleinik N, Xu B, Vikas, Kontaridis MI, Rheinstädter MC, Ogretmen B, Menick DR, McCarthy JR. Biomimetic Nanomaterials for the Immunomodulation of the Cardiosplenic Axis Postmyocardial Infarction. Adv Mater 2024; 36:e2304615. [PMID: 37934471 PMCID: PMC10922695 DOI: 10.1002/adma.202304615] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 10/16/2023] [Indexed: 11/08/2023]
Abstract
The spleen is an important mediator of both adaptive and innate immunity. As such, attempts to modulate the immune response provided by the spleen may be conducive to improved outcomes for numerous diseases throughout the body. Here, biomimicry is used to rationally design nanomaterials capable of splenic retention and immunomodulation for the treatment of disease in a distant organ, the postinfarct heart. Engineered senescent erythrocyte-derived nanotheranostic (eSENTs) are generated, demonstrating significant uptake by the immune cells of the spleen including T and B cells, as well as monocytes and macrophages. When loaded with suberoylanilide hydroxamic acid (SAHA), the nanoagents exhibit a potent therapeutic effect, reducing infarct size by 14% at 72 h postmyocardial infarction when given as a single intravenous dose 2 h after injury. These results are supportive of the hypothesis that RBC-derived biomimicry may provide new approaches for the targeted modulation of the pathological processes involved in myocardial infarction, thus further experiments to decisively confirm the mechanisms of action are currently underway. This novel concept may have far-reaching applicability for the treatment of a number of both acute and chronic conditions where the immune responses are either stimulated or suppressed by the splenic (auto)immune milieu.
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Affiliation(s)
- Rajendran Jc Bose
- Department of Biomedical Research and Translational Medicine, Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Chase W Kessinger
- Department of Biomedical Research and Translational Medicine, Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Tajinder Dhammu
- Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Toolika Singh
- Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Miller W Shealy
- Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Khanh Ha
- Department of Biomedical Research and Translational Medicine, Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Rena Collandra
- Department of Biomedical Research and Translational Medicine, Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Fernando J Garcia
- Department of Radiology, Stanford University School of Medicine, Stanford, CA, 94305, USA
| | - Natalia Oleinik
- Department of Biochemistry and Molecular Biology, and Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Bing Xu
- Department of Biomedical Research and Translational Medicine, Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Vikas
- Department of Biomedical Research and Translational Medicine, Masonic Medical Research Institute, Utica, NY, 13501, USA
| | - Maria I Kontaridis
- Department of Biomedical Research and Translational Medicine, Masonic Medical Research Institute, Utica, NY, 13501, USA
- Department of Medicine, Division of Cardiology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, 02115, USA
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, 02115, USA
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Besim Ogretmen
- Department of Biochemistry and Molecular Biology, and Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Donald R Menick
- Department of Medicine, Division of Cardiology, Medical University of South Carolina, Charleston, SC, 29425, USA
- Ralph H. Johnson Veterans Affairs Medical Center, Charleston, SC, 29401, USA
| | - Jason R McCarthy
- Department of Biomedical Research and Translational Medicine, Masonic Medical Research Institute, Utica, NY, 13501, USA
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3
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Himbert S, Gaboo D, Brookes E, Nagle JF, Rheinstädter MC. MEDUSA: A cloud-based tool for the analysis of X-ray diffuse scattering to obtain the bending modulus from oriented membrane stacks. PLoS Comput Biol 2024; 20:e1011749. [PMID: 38190400 PMCID: PMC10798642 DOI: 10.1371/journal.pcbi.1011749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 01/19/2024] [Accepted: 12/11/2023] [Indexed: 01/10/2024] Open
Abstract
An important mechanical property of cells is their membrane bending modulus, κ. Here, we introduce MEDUSA (MEmbrane DiffUse Scattering Analysis), a cloud-based analysis tool to determine the bending modulus, κ, from the analysis of X-ray diffuse scattering. MEDUSA uses GPU (graphics processing unit) accelerated hardware and a parallelized algorithm to run the calculations efficiently in a few seconds. MEDUSA's graphical user interface allows the user to upload 2-dimensional data collected from different sources, perform background subtraction and distortion corrections, select regions of interest, run the fitting procedure and output the fitted parameters, the membranes' bending modulus κ, and compressional modulus B.
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Affiliation(s)
- Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
- Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Dorian Gaboo
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
- Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Emre Brookes
- Department of Chemistry and Biochemistry, University of Montana, Missoula, Montana, United States of America
| | - John F. Nagle
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania, United States of America
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
- Origins Institute, McMaster University, Hamilton, Ontario, Canada
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4
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Dujardin A, Himbert S, Pudritz R, Rheinstädter MC. The Formation of RNA Pre-Polymers in the Presence of Different Prebiotic Mineral Surfaces Studied by Molecular Dynamics Simulations. Life (Basel) 2022; 13:life13010112. [PMID: 36676060 PMCID: PMC9860743 DOI: 10.3390/life13010112] [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] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 12/21/2022] [Accepted: 12/24/2022] [Indexed: 01/04/2023]
Abstract
We used all-atom Molecular Dynamics (MD) computer simulations to study the formation of pre-polymers between the four nucleotides in RNA (AMP, UMP, CMP, GMP) in the presence of different substrates that could have been present in a prebiotic environment. Pre-polymers are C3'-C5' hydrogen-bonded nucleotides that have been suggested to be the precursors of phosphodiester-bonded RNA polymers. We simulated wet-dry cycles by successively removing water molecules from the simulations, from ~60 to 3 water molecules per nucleotide. The nine substrates in this study include three clay minerals, one mica, one phosphate mineral, one silica, and two metal oxides. The substrates differ in their surface charge and ability to form hydrogen bonds with the nucleotides. From the MD simulations, we quantify the interactions between different nucleotides, and between nucleotides and substrates. For comparison, we included graphite as an inert substrate, which is not charged and cannot form hydrogen bonds. We also simulated the dehydration of a nucleotide-only system, which mimics the drying of small droplets. The number of hydrogen bonds between nucleotides and nucleotides and substrates was found to increase significantly when water molecules were removed from the systems. The largest number of C3'-C5' hydrogen bonds between nucleotides occurred in the graphite and nucleotide-only systems. While the surface of the substrates led to an organization and periodic arrangement of the nucleotides, none of the substrates was found to be a catalyst for pre-polymer formation, neither at full hydration, nor when dehydrated. While confinement and dehydration seem to be the main drivers for hydrogen bond formation, substrate interactions reduced the interactions between nucleotides in all cases. Our findings suggest that small supersaturated water droplets that could have been produced by geysers or springs on the primitive Earth may play an important role in non-enzymatic RNA polymerization.
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Affiliation(s)
- Alix Dujardin
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4M1, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4M1, Canada
| | - Ralph Pudritz
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4M1, Canada
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4M1, Canada
- Correspondence: ; Tel.: +1-(905)-525-9140-23134; Fax: +1-(905)-546-1252
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5
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Krivić H, Himbert S, Rheinstädter MC. Perspective on the Application of Erythrocyte Liposome-Based Drug Delivery for Infectious Diseases. Membranes (Basel) 2022; 12:1226. [PMID: 36557133 PMCID: PMC9785899 DOI: 10.3390/membranes12121226] [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] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Accepted: 11/29/2022] [Indexed: 06/17/2023]
Abstract
Nanoparticles are explored as drug carriers with the promise for the treatment of diseases to increase the efficacy and also reduce side effects sometimes seen with conventional drugs. To accomplish this goal, drugs are encapsulated in or conjugated to the nanocarriers and selectively delivered to their targets. Potential applications include immunization, the delivery of anti-cancer drugs to tumours, antibiotics to infections, targeting resistant bacteria, and delivery of therapeutic agents to the brain. Despite this great promise and potential, drug delivery systems have yet to be established, mainly due to their limitations in physical instability and rapid clearance by the host's immune response. Recent interest has been taken in using red blood cells (RBC) as drug carriers due to their naturally long circulation time, flexible structure, and direct access to many target sites. This includes coating of nanoparticles with the membrane of red blood cells, and the fabrication and manipulation of liposomes made of the red blood cells' cytoplasmic membrane. The properties of these erythrocyte liposomes, such as charge and elastic properties, can be tuned through the incorporation of synthetic lipids to optimize physical properties and the loading efficiency and retention of different drugs. Specificity can be established through the anchorage of antigens and antibodies in the liposomal membrane to achieve targeted delivery. Although still at an early stage, this erythrocyte-based platform shows first promising results in vitro and in animal studies. However, their full potential in terms of increased efficacy and side effect minimization still needs to be explored in vivo.
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Affiliation(s)
- Hannah Krivić
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4M1, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4M1, Canada
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4M1, Canada
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6
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Krivić H, Himbert S, Sun R, Feigis M, Rheinstädter MC. Erythro-PmBs: A Selective Polymyxin B Delivery System Using Antibody-Conjugated Hybrid Erythrocyte Liposomes. ACS Infect Dis 2022; 8:2059-2072. [PMID: 36173819 DOI: 10.1021/acsinfecdis.2c00017] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
As a result of the growing worldwide antibiotic resistance crisis, many currently existing antibiotics have become ineffective due to bacteria developing resistive mechanisms. There are a limited number of potent antibiotics that are successful at suppressing microbial growth, such as polymyxin B (PmB); however, these are often deemed as a last resort due to their toxicity. We present a novel PmB delivery system constructed by conjugating hybrid erythrocyte liposomes with antibacterial antibodies to combine a high loading efficiency with guided delivery. The retention of PmB is enhanced by incorporating negatively charged lipids into the red blood cells' cytoplasmic membrane (RBCcm). Anti-Escherichia coli antibodies are attached to these hybrid erythrocyte liposomes by the inclusion of DSPE-PEG maleimide linkers. We show that these erythro-PmBs have a loading efficiency of ∼90% and are effective in delivering PmB to E. coli, with values for the minimum inhibitory concentration (MIC) being comparable to those of free PmB. The MIC values for Klebsiella aerogenes, however, significantly increased well beyond the resistant breakpoint, indicating that the inclusion of the anti-E. coli antibodies enables the erythro-PmBs to selectively deliver antibiotics to specific targets.
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Affiliation(s)
- Hannah Krivić
- Department of Physics and Astronomy, McMaster University, HamiltonL8S 4M1, Ontario, Canada.,Origins Institute, McMaster University, HamiltonL8S 4M1, Ontario, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, HamiltonL8S 4M1, Ontario, Canada.,Origins Institute, McMaster University, HamiltonL8S 4M1, Ontario, Canada
| | - Ruthie Sun
- Department of Physics and Astronomy, McMaster University, HamiltonL8S 4M1, Ontario, Canada.,Origins Institute, McMaster University, HamiltonL8S 4M1, Ontario, Canada
| | - Michal Feigis
- Department of Physics and Astronomy, McMaster University, HamiltonL8S 4M1, Ontario, Canada.,Origins Institute, McMaster University, HamiltonL8S 4M1, Ontario, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, HamiltonL8S 4M1, Ontario, Canada.,Origins Institute, McMaster University, HamiltonL8S 4M1, Ontario, Canada
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7
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Himbert S, Rheinstädter MC. Structural and mechanical properties of the red blood cell’s cytoplasmic membrane seen through the lens of biophysics. Front Physiol 2022; 13:953257. [PMID: 36171967 PMCID: PMC9510598 DOI: 10.3389/fphys.2022.953257] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 08/15/2022] [Indexed: 11/27/2022] Open
Abstract
Red blood cells (RBCs) are the most abundant cell type in the human body and critical suppliers of oxygen. The cells are characterized by a simple structure with no internal organelles. Their two-layered outer shell is composed of a cytoplasmic membrane (RBCcm) tethered to a spectrin cytoskeleton allowing the cell to be both flexible yet resistant against shear stress. These mechanical properties are intrinsically linked to the molecular composition and organization of their shell. The cytoplasmic membrane is expected to dominate the elastic behavior on small, nanometer length scales, which are most relevant for cellular processes that take place between the fibrils of the cytoskeleton. Several pathologies have been linked to structural and compositional changes within the RBCcm and the cell’s mechanical properties. We review current findings in terms of RBC lipidomics, lipid organization and elastic properties with a focus on biophysical techniques, such as X-ray and neutron scattering, and Molecular Dynamics simulations, and their biological relevance. In our current understanding, the RBCcm’s structure is patchy, with nanometer sized liquid ordered and disordered lipid, and peptide domains. At the same time, it is surprisingly soft, with bending rigidities κ of 2–4 kBT. This is in strong contrast to the current belief that a high concentration of cholesterol results in stiff membranes. This extreme softness is likely the result of an interaction between polyunsaturated lipids and cholesterol, which may also occur in other biological membranes. There is strong evidence in the literature that there is no length scale dependence of κ of whole RBCs.
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Affiliation(s)
- Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Origins Institute, McMaster University, Hamilton, ON, Canada
- *Correspondence: Sebastian Himbert, ; Maikel C. Rheinstädter,
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Origins Institute, McMaster University, Hamilton, ON, Canada
- *Correspondence: Sebastian Himbert, ; Maikel C. Rheinstädter,
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8
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Himbert S, Gastaldo IP, Ahmed R, Pomier KM, Cowbrough B, Jahagirdar D, Ros S, Juhasz J, Stöver HDH, Ortega J, Melacini G, Bowdish DME, Rheinstädter MC. Erythro-VLPs: Anchoring SARS-CoV-2 spike proteins in erythrocyte liposomes. PLoS One 2022; 17:e0263671. [PMID: 35275926 PMCID: PMC8916654 DOI: 10.1371/journal.pone.0263671] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Accepted: 01/24/2022] [Indexed: 12/12/2022] Open
Abstract
Novel therapeutic strategies are needed to control the SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic. Here, we present a protocol to anchor the SARS-CoV-2 spike (S-)protein in the cytoplasmic membranes of erythrocyte liposomes. A surfactant was used to stabilize the S-protein’s structure in the aqueous environment before insertion and to facilitate reconstitution of the S-proteins in the erythrocyte membranes. The insertion process was studied using coarse grained Molecular Dynamics (MD) simulations. Liposome formation and S-protein anchoring was studied by dynamic light scattering (DLS), ELV-protein co-sedimentation assays, fluorescent microcopy and cryo-TEM. The Erythro-VLPs (erythrocyte based virus like particles) have a well defined size of ∼200 nm and an average protein density on the outer membrane of up to ∼300 proteins/μm2. The correct insertion and functional conformation of the S-proteins was verified by dose-dependent binding to ACE-2 (angiotensin converting enzyme 2) in biolayer interferometry (BLI) assays. Seroconversion was observed in a pilot mouse trial after 14 days when administered intravenously, based on enzyme-linked immunosorbent assays (ELISA). This red blood cell based platform can open novel possibilities for therapeutics for the coronavirus disease (COVID-19) including variants, and other viruses in the future.
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Affiliation(s)
- Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Origins Institute, McMaster University, Hamilton, ON, Canada
| | - Isabella Passos Gastaldo
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Origins Institute, McMaster University, Hamilton, ON, Canada
| | - Rashik Ahmed
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton ON, Canada
| | - Karla Martinez Pomier
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton ON, Canada
| | - Braeden Cowbrough
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
| | - Dushyant Jahagirdar
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
| | - Samantha Ros
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON, Canada
| | - Janos Juhasz
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Juravinski Cancer Centre, Department of Medical Physics, Hamilton, ON, Canada
| | - Harald D. H. Stöver
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON, Canada
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
| | - Giuseppe Melacini
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON, Canada
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton ON, Canada
| | - Dawn M. E. Bowdish
- Department of Medicine, McMaster University, Hamilton, ON, Canada
- McMaster Immunology Research Centre, McMaster University, Hamilton, ON, Canada
- Firestone Institute for Respiratory Health, St. Joseph’s Healthcare, Hamilton, ON, Canada
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Origins Institute, McMaster University, Hamilton, ON, Canada
- * E-mail:
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9
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Himbert S, Qadri SM, Sheffield WP, Schubert P, D’Alessandro A, Rheinstädter MC. Blood bank storage of red blood cells increases RBC cytoplasmic membrane order and bending rigidity. PLoS One 2021; 16:e0259267. [PMID: 34767588 PMCID: PMC8589153 DOI: 10.1371/journal.pone.0259267] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/17/2021] [Indexed: 12/05/2022] Open
Abstract
Blood banks around the world store blood components for several weeks ensuring its availability for transfusion medicine. Red blood cells (RBCs) are known to undergo compositional changes during storage, which may impact the cells' function and eventually the recipients' health. We extracted the RBC's cytoplasmic membrane (RBCcm) to study the effect of storage on the membranes' molecular structure and bending rigidity by a combination of X-ray diffraction (XRD), X-ray diffuse scattering (XDS) and coarse grained Molecular Dynamics (MD) simulations. Blood was stored in commercial blood bags for 2 and 5 weeks, respectively and compared to freshly drawn blood. Using mass spectrometry, we measured an increase of fatty acids together with a slight shift towards shorter tail lengths. We observe an increased fraction (6%) of liquid ordered (lo) domains in the RBCcms with storage time, and an increased lipid packing in these domains, leading to an increased membrane thickness and membrane order. The size of both, lo and liquid disordered (ld) lipid domains was found to decrease with increased storage time by up to 25%. XDS experiments reveal a storage dependent increase in the RBCcm's bending modulus κ by a factor of 2.8, from 1.9 kBT to 5.3 kBT. MD simulations were conducted in the absence of proteins. The results show that the membrane composition has a small contribution to the increased bending rigidity and suggests additional protein-driven mechanisms.
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Affiliation(s)
- Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Origins Institute, McMaster University, Hamilton, ON, Canada
| | - Syed M. Qadri
- Faculty of Health Sciences, Ontario Tech University, Oshawa, ON, Canada
| | - William P. Sheffield
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada
- Centre for Innovation, Canadian Blood Services, Hamilton, ON, Canada
| | - Peter Schubert
- Centre for Innovation, Canadian Blood Services, Vancouver, BC, Canada
- Centre for Blood Research, University of British Columbia, Vancouver, BC, Canada
| | - Angelo D’Alessandro
- University of Colorado Denver-Anschutz Medical Campus, Aurora, CO, United States of America
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
- Origins Institute, McMaster University, Hamilton, ON, Canada
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Kassem N, Araya-Secchi R, Bugge K, Barclay A, Steinocher H, Khondker A, Wang Y, Lenard AJ, Bürck J, Sahin C, Ulrich AS, Landreh M, Pedersen MC, Rheinstädter MC, Pedersen PA, Lindorff-Larsen K, Arleth L, Kragelund BB. Order and disorder-An integrative structure of the full-length human growth hormone receptor. Sci Adv 2021; 7:7/27/eabh3805. [PMID: 34193419 PMCID: PMC8245047 DOI: 10.1126/sciadv.abh3805] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 05/18/2021] [Indexed: 05/13/2023]
Abstract
Because of its small size (70 kilodalton) and large content of structural disorder (>50%), the human growth hormone receptor (hGHR) falls between the cracks of conventional high-resolution structural biology methods. Here, we study the structure of the full-length hGHR in nanodiscs with small-angle x-ray scattering (SAXS) as the foundation. We develop an approach that combines SAXS, x-ray diffraction, and NMR spectroscopy data obtained on individual domains and integrate these through molecular dynamics simulations to interpret SAXS data on the full-length hGHR in nanodiscs. The hGHR domains reorient freely, resulting in a broad structural ensemble, emphasizing the need to take an ensemble view on signaling of relevance to disease states. The structure provides the first experimental model of any full-length cytokine receptor in a lipid membrane and exemplifies how integrating experimental data from several techniques computationally may access structures of membrane proteins with long, disordered regions, a widespread phenomenon in biology.
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Affiliation(s)
- Noah Kassem
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen N, Denmark
| | - Raul Araya-Secchi
- X-ray and Neutron Science, The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Bugge
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen N, Denmark
| | - Abigail Barclay
- X-ray and Neutron Science, The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | - Helena Steinocher
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen N, Denmark
| | - Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
| | - Yong Wang
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen N, Denmark
| | - Aneta J Lenard
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen N, Denmark
| | - Jochen Bürck
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021 Karlsruhe, Germany
| | - Cagla Sahin
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm 171 65, Sweden
| | - Anne S Ulrich
- Institute of Biological Interfaces (IBG-2), Karlsruhe Institute of Technology (KIT), POB 3640, 76021 Karlsruhe, Germany
| | - Michael Landreh
- Department of Microbiology, Tumor, and Cell Biology, Karolinska Institutet, Stockholm 171 65, Sweden
| | - Martin Cramer Pedersen
- X-ray and Neutron Science, The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
| | | | - Per Amstrup Pedersen
- Department of Biology, University of Copenhagen, Universitetsparken 13, DK-2100 Copenhagen, Denmark
| | - Kresten Lindorff-Larsen
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen N, Denmark.
| | - Lise Arleth
- X-ray and Neutron Science, The Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark.
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, Department of Biology, University of Copenhagen, Ole Maaløes vej 5, 2200 Copenhagen N, Denmark.
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11
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Zou X, Himbert S, Dujardin A, Juhasz J, Ros S, Stöver HDH, Rheinstädter MC. Curcumin and Homotaurine Suppress Amyloid-β 25-35 Aggregation in Synthetic Brain Membranes. ACS Chem Neurosci 2021; 12:1395-1405. [PMID: 33826295 DOI: 10.1021/acschemneuro.1c00057] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Amyloid-β (Aβ) peptides spontaneously aggregate into β- and cross-β-sheets in model brain membranes. These nanometer sized can fuse into larger micrometer sized clusters and become extracellular and serve as nuclei for further plaque and fibril growth. Curcumin and homotaurine represent two different types of Aβ aggregation inhibitors. While homotaurine is a peptic antiaggregant that binds to amyloid peptides, curcumin is a nonpeptic molecule that can inhibit aggregation by changing membrane properties. By using optical and fluorescent microscopy, X-ray diffraction, and UV-vis spectroscopy, we study the effect of curcumin and homotaurine on Aβ25-35 aggregates in synthetic brain membranes. Both molecules partition spontaneously and uniformly in membranes and do not lead to observable membrane defects or disruption in our experiments. Both curcumin and homotaurine were found to significantly reduce the number of small, nanoscopic Aβ aggregates and the corresponding β- and cross-β-sheet signals. While a number of research projects focus on potential drug candidates that target Aβ peptides directly, membrane-lipid therapy explores membrane-mediated pathways to suppress peptide aggregation. Based on the results obtained, we conclude that membrane active drugs can be as efficient as peptide targeting drugs in inhibiting amyloid aggregation in vitro.
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Affiliation(s)
- Xingyuan Zou
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Alix Dujardin
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4L8, Canada
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Janos Juhasz
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Department of Medical Physics, Juravinski Cancer Centre, Hamilton, ON L8V 5C2, Canada
| | - Samantha Ros
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Harald D. H. Stöver
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON L8S 4L8, Canada
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, ON L8S 4L8, Canada
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12
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Himbert S, Zhang L, Alsop RJ, Cristiglio V, Fragneto G, Rheinstädter MC. Anesthetics significantly increase the amount of intramembrane water in lipid membranes. Soft Matter 2020; 16:9674-9682. [PMID: 32869047 DOI: 10.1039/d0sm01271h] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The potency of anesthesia was directly linked to the partitioning of the drug molecules in cell membranes by Meyer and Overton. Many molecules interact with lipid bilayers and lead to structural and functional changes. It remains an open question which change in membrane properties is responsible for a potential anesthetic effect or if anesthetics act by binding to direct targets. We studied the effect of ethanol, diethyl ether and isoflurane on the water distribution in lipid bilayers by combining all-atom molecular dynamics simulations and neutron diffraction experiments. The simulations show strong membrane-drug interactions with partitioning coefficients of 38%, 92% and 100% for ethanol, diethyl ether and isoflurane, respectively, and provide evidence for an increased water partitioning in the membrane core. The amount of intramembrane water molecules was experimentally determined by selectively deuterium labeling lipids, anesthetic drug and water molecules in neutron diffraction experiments. Four additional water molecules per lipid were observed in the presence of ethanol. Diethyl ether and isoflurane were found to significantly increase the amount of intramembrane water by 25% (8 water molecules). This increase in intramembrane water may contribute to the non-specific interactions between anesthetics and lipid membranes.
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Affiliation(s)
- Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, ABB-241, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
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13
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Gastaldo IP, Himbert S, Ram U, Rheinstädter MC. The Effects of Resveratrol, Caffeine, β-Carotene, and Epigallocatechin Gallate (EGCG) on Amyloid- β 25 -- 35 Aggregation in Synthetic Brain Membranes. Mol Nutr Food Res 2020; 64:e2000632. [PMID: 32981185 DOI: 10.1002/mnfr.202000632] [Citation(s) in RCA: 8] [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: 07/02/2020] [Indexed: 01/08/2023]
Abstract
SCOPE Alzheimer's disease is a neurodegenerative condition marked by the formation and aggregation of amyloid-β (Aβ) peptides. There exists, to this day, no cure or effective prevention for the disease; however, there is evidence that a healthy diet and certain food products can slow down first occurrence and progression. To investigate if food ingredients can interact with peptide aggregates, synthetic membranes that contained aggregates consisting of cross-β sheets of the membrane active fragment A β 25 -- 35 are prepared. METHODS AND RESULTS The impact of resveratrol, found in grapes, caffeine, the main active ingredient in coffee, β-carotene, found in orange fruits and vegetables, and epigallocatechin gallate (EGCG), a component of green tea, on the size and volume fraction of Aβ aggregates is studied using optical and fluorescence microscopy, X-ray diffraction, UV-vis spectroscopy, and molecular dynamics simulations. All compounds are membrane active and spontaneously partitioned in the synthetic brain membranes. While resveratrol and caffeine lead to membrane thickening and reduced membrane fluidity, β-carotene and EGCG preserve or increase fluidity. CONCLUSION Resveratrol and caffeine do not reduce the volume fraction of peptide aggregates while β-carotene significantly reduces plaque size. Interestingly, EGCG dissolves peptide aggregates and significantly decreases the corresponding cross-β and β-sheet signals.
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Affiliation(s)
- Isabella P Gastaldo
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, L8S 4M1, Canada.,Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - Udbhav Ram
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, L8S 4M1, Canada
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14
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Bider RC, Lluka T, Himbert S, Khondker A, Qadri SM, Sheffield WP, Rheinstädter MC. Stabilization of Lipid Membranes through Partitioning of the Blood Bag Plasticizer Di-2-ethylhexyl phthalate (DEHP). Langmuir 2020; 36:11899-11907. [PMID: 32903014 DOI: 10.1021/acs.langmuir.0c01964] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The safe storage of blood is of fundamental importance to health care systems all over the world. Currently, plastic bags are used for the collection and storage of donated blood and are typically made of poly(vinyl chloride) (PVC) plasticized with di-2-ethylhexyl phthalate (DEHP). DEHP is known to migrate into packed red blood cells (RBC) and has been found to extend their shelf life. It has been speculated that DEHP incorporates itself into the RBC membrane and alters membrane properties, thereby reducing susceptibility to hemolysis and morphological deterioration. Here, we used high-resolution X-ray diffraction and molecular dynamics (MD) simulations to study the interaction between DEHP and model POPC lipid membranes at high (9 mol %) and low (1 mol %) concentrations of DEHP. At both concentrations, DEHP was found to spontaneously partition into the bilayer. At high concentrations, DEHP molecules were found to aggregate in the aqueous phase before inserting as clusters into the membrane. The presence of DEHP in the bilayers resulted in subtle, yet statistically significant, alterations in several membrane properties in both the X-ray diffraction experiments and MD simulations. DEHP led to (1) an increase of membrane width and (2) an increase in the area per lipid. It was also found to (3) increase the deuterium order parameter, however, (4) decrease membrane orientation, indicating the formation of thicker, stiffer membranes with increased local curvature. The observed effects of DEHP on lipid bilayers may help to better understand its effect on RBC membranes in increasing the longevity of stored blood by improving membrane stability.
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Affiliation(s)
- Renée-Claude Bider
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Telmah Lluka
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Adree Khondker
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Syed M Qadri
- Faculty of Health Sciences, Ontario Tech University, Oshawa, Ontario L1G 0C5, Canada
| | - William P Sheffield
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario L8S 4M1, Canada
- Centre for Innovation, Canadian Blood Services, Hamilton, Ontario L8S 4M1, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, Ontario L8S 4M1, Canada
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15
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Khondker A, Bider RC, Passos-Gastaldo I, Wright GD, Rheinstädter MC. Membrane interactions of non-membrane targeting antibiotics: The case of aminoglycosides, macrolides, and fluoroquinolones. Biochim Biophys Acta Biomembr 2020; 1863:183448. [PMID: 32828850 DOI: 10.1016/j.bbamem.2020.183448] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 08/09/2020] [Accepted: 08/11/2020] [Indexed: 11/25/2022]
Abstract
Numerous antibiotics are known to target intracellular pathways, such as protein translation or DNA replication. Membrane transporters typically regulate drug uptake; however, little is known about direct interactions between these antibiotics and the cell membranes. Here, we studied the interactions between different aminoglycosides (kanamycin, gentamicin, streptomycin, neomycin), macrolides (azithromycin, clarithromycin, erythromycin), and fluoroquinolones (ciprofloxacin, levofloxacin) with bacterial membrane mimics to determine drug partitioning and potential drug-induced membrane disruption. The antibiotics' exact location in the bilayers and their effect on membrane thickness and fluidity were determined from high-resolution X-ray diffraction. While the antibiotics did not change membrane thickness at low (1:100 drug/lipid) or high (1:10 drug/lipid) concentrations, they were found to increase membrane disorder in a dose-dependent manner. However, no membrane damage, such as membrane disruption or pore formation, was observed for any of the antibiotics. To note, all antibiotics partitioned into the lipid head groups, while macrolides and fluoroquinolones also partitioned into the bilayer core. The results suggest that the bacterial membrane is relatively inert in the direct mechanisms of actions of these antibiotics.
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Affiliation(s)
- Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Origins Institute, McMaster University, Hamilton, Ontario, Canada; Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Renée-Claude Bider
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Isabella Passos-Gastaldo
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Origins Institute, McMaster University, Hamilton, Ontario, Canada; Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Gerard D Wright
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada; Michael G. DeGroote Institute for Infectious Disease Research, McMaster University, Hamilton, Ontario, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Origins Institute, McMaster University, Hamilton, Ontario, Canada.
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16
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Ahmed R, Huang J, Weber DK, Gopinath T, Veglia G, Akimoto M, Khondker A, Rheinstädter MC, Huynh V, Wylie RG, Bozelli JC, Epand RM, Melacini G. Molecular Mechanism for the Suppression of Alpha Synuclein Membrane Toxicity by an Unconventional Extracellular Chaperone. J Am Chem Soc 2020; 142:9686-9699. [DOI: 10.1021/jacs.0c01894] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Affiliation(s)
- Rashik Ahmed
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton ON L8S 4M1, Canada
| | - Jinfeng Huang
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton ON L8S 4M1, Canada
| | - Daniel K. Weber
- Department of Biochemistry, Chemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Tata Gopinath
- Department of Biochemistry, Chemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Gianluigi Veglia
- Department of Biochemistry, Chemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, United States
| | - Madoka Akimoto
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton ON L8S 4M1, Canada
| | - Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton ON L8S 4M1, Canada
| | | | - Vincent Huynh
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton ON L8S 4M1, Canada
| | - Ryan G. Wylie
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton ON L8S 4M1, Canada
| | - José C. Bozelli
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton ON L8S 4M1, Canada
| | - Richard M. Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton ON L8S 4M1, Canada
| | - Giuseppe Melacini
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton ON L8S 4M1, Canada
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton ON L8S 4M1, Canada
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17
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Cholak E, Bugge K, Khondker A, Gauger K, Pedraz-Cuesta E, Pedersen ME, Bucciarelli S, Vestergaard B, Pedersen SF, Rheinstädter MC, Langkilde AE, Kragelund BB. Avidity within the N-terminal anchor drives α-synuclein membrane interaction and insertion. FASEB J 2020; 34:7462-7482. [PMID: 32277854 DOI: 10.1096/fj.202000107r] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [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: 01/14/2020] [Revised: 03/02/2020] [Accepted: 03/17/2020] [Indexed: 12/25/2022]
Abstract
In the brain, α-synuclein (aSN) partitions between free unbound cytosolic and membrane bound forms modulating both its physiological and pathological role and complicating its study due to structural heterogeneity. Here, we use an interdisciplinary, synergistic approach to characterize the properties of aSN:lipid mixtures, isolated aSN:lipid co-structures, and aSN in mammalian cells. Enabled by the isolation of the membrane-bound state, we show that within the previously described N-terminal membrane anchor, membrane interaction relies both on an N-terminal tail (NTT) head group layer insertion of 14 residues and a folded-upon-binding helix at the membrane surface. Both binding events must be present; if, for example, the NTT insertion is lost, the membrane affinity of aSN is severely compromised and formation of aSN:lipid co-structures hampered. In mammalian cells, compromised cooperativity results in lowered membrane association. Thus, avidity within the N-terminal anchor couples N-terminal insertion and helical surface binding, which is crucial for aSN membrane interaction and cellular localization, and may affect membrane fusion.
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Affiliation(s)
- Ersoy Cholak
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Katrine Bugge
- Structural Biology and NMR Laboratory, The Linderstrøm-Lang Centre for Protein Science and Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada
| | - Kimmie Gauger
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Elena Pedraz-Cuesta
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Saskia Bucciarelli
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Bente Vestergaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Stine F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | | | - Annette Eva Langkilde
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- Structural Biology and NMR Laboratory, The Linderstrøm-Lang Centre for Protein Science and Department of Biology, University of Copenhagen, Copenhagen, Denmark
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18
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Saem S, Shahid O, Khondker A, Moran-Hidalgo C, Rheinstädter MC, Moran-Mirabal J. Benchtop-fabricated lipid-based electrochemical sensing platform for the detection of membrane disrupting agents. Sci Rep 2020; 10:4595. [PMID: 32165701 PMCID: PMC7067837 DOI: 10.1038/s41598-020-61561-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 02/28/2020] [Indexed: 11/22/2022] Open
Abstract
There are increasing concerns about the danger that water-borne pathogens and pollutants pose to the public. Of particular importance are those that disrupt the plasma membrane, since loss of membrane integrity can lead to cell death. Currently, quantitative assays to detect membrane-disrupting (lytic) agents are done offsite, leading to long turnaround times and high costs, while existing colorimetric point-of-need solutions often sacrifice sensitivity. Thus, portable and highly sensitive solutions are needed to detect lytic agents for health and environmental monitoring. Here, a lipid-based electrochemical sensing platform is introduced to rapidly detect membrane-disrupting agents. The platform combines benchtop fabricated microstructured electrodes (MSEs) with lipid membranes. The sensing mechanism of the lipid-based platform relies on stacked lipid membranes serving as passivating layers that when disrupted generate electrochemical signals proportional to the membrane damage. The MSE topography, membrane casting and annealing conditions were optimized to yield the most reproducible and sensitive devices. We used the sensors to detect membrane-disrupting agents sodium dodecyl sulfate and Polymyxin-B within minutes and with limits of detection in the ppm regime. This study introduces a platform with potential for the integration of complex membranes on MSEs towards the goal of developing Membrane-on-Chip sensing devices.
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Affiliation(s)
- Sokunthearath Saem
- McMaster University, Department of Chemistry and Chemical Biology, Hamilton, L8S 4L8, Canada
| | - Osama Shahid
- McMaster University, Department of Chemistry and Chemical Biology, Hamilton, L8S 4L8, Canada
| | - Adree Khondker
- McMaster University, Department of Physics and Astronomy, Hamilton, L8S 4L8, Canada
| | - Camila Moran-Hidalgo
- McMaster University, Department of Chemistry and Chemical Biology, Hamilton, L8S 4L8, Canada
| | | | - Jose Moran-Mirabal
- McMaster University, Department of Chemistry and Chemical Biology, Hamilton, L8S 4L8, Canada.
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19
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Abstract
In our recent Communications Biology article, we reported on the biophysical mechanism of resistance for polymyxin antibiotics in bacterial membranes. The emergence of plasmid-borne colistin resistance poses a threat to our last line of defense against many pathogens. Here, we outline the current understanding of mcr-1-mediated polymyxin resistance, and propose future directions for membrane-targeting antibiotic research. Adree Khondker and Maikel Rheinstadter discuss how bacteria escape being killed by polymyxin antibiotics. Touching on their recent Communications Biology paper, they elaborate on the mechanism by which the bacterial membrane becomes resistant and on future directions to take in order to understand this phenomenon.
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Affiliation(s)
- Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada.,Faculty of Medicine, University of Toronto, Toronto, ON, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, Canada. .,Origins Institute, McMaster University, Hamilton, ON, Canada.
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20
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Majcher MJ, McInnis CL, Himbert S, Alsop RJ, Kinio D, Bleuel M, Rheinstädter MC, Smeets NMB, Hoare T. Photopolymerized Starchstarch Nanoparticle (SNP) network hydrogels. Carbohydr Polym 2020; 236:115998. [PMID: 32172832 DOI: 10.1016/j.carbpol.2020.115998] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [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: 11/27/2019] [Revised: 02/08/2020] [Accepted: 02/11/2020] [Indexed: 12/11/2022]
Abstract
Starch is an attractive biomaterial given its low cost and high protein repellency, but its use in forming functional hydrogels is limited by its high viscosity and crystallinity. Herein, we demonstrate the use of fully amorphous starch nanoparticles (SNPs) as functional hydrogel building blocks that overcome these challenges. Methacrylation of SNPs enables hydrogel formation via photopolymerization, with the low viscosity of SNPs enabling facile preparation of pre-gel suspensions of up to 35 wt% SNPs relative to <10 wt% with linear starch. Small angle neutron scattering indicates a significantly different microstructure in SNP-based hydrogels compared to linear starch-based hydrogels due to the balance between inter- and intra-particle crosslinks, consistent with SNPs forming denser and stiffer hydrogels. Functionalized SNPs are highly cytocompatible at degree of substitution values <0.25 and, once gelled, can effectively repel cell adhesion. The physicochemical versatility and biological functionality of SNP-based hydrogels offer potential in various applications.
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Affiliation(s)
- Michael J Majcher
- Department of Chemical Engineering, McMaster University, 1280 Main Street, West Hamilton, ON L8S 4L8, Canada.
| | - Carter L McInnis
- Department of Chemical Engineering, McMaster University, 1280 Main Street, West Hamilton, ON L8S 4L8, Canada.
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, 1280 Main Street, West Hamilton, ON L8S 4L8, Canada.
| | - Richard J Alsop
- Department of Physics and Astronomy, McMaster University, 1280 Main Street, West Hamilton, ON L8S 4L8, Canada.
| | - Dennis Kinio
- EcoSynthetix Inc., 3365 Mainway, Burlington, ON L7M 1A6, Canada.
| | - Markus Bleuel
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, MD 20899-6100, United States.
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, 1280 Main Street, West Hamilton, ON L8S 4L8, Canada.
| | - Niels M B Smeets
- EcoSynthetix Inc., 3365 Mainway, Burlington, ON L7M 1A6, Canada.
| | - Todd Hoare
- Department of Chemical Engineering, McMaster University, 1280 Main Street, West Hamilton, ON L8S 4L8, Canada.
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21
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Himbert S, Blacker MJ, Kihm A, Pauli Q, Khondker A, Yang K, Sinjari S, Johnson M, Juhasz J, Wagner C, Stöver HDH, Rheinstädter MC. Hybrid Erythrocyte Liposomes: Functionalized Red Blood Cell Membranes for Molecule Encapsulation. ACTA ACUST UNITED AC 2020; 4:e1900185. [PMID: 32293142 DOI: 10.1002/adbi.201900185] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [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: 08/14/2019] [Revised: 11/26/2019] [Indexed: 12/28/2022]
Abstract
The modification of erythrocyte membrane properties provides a new tool towards improved drug delivery and biomedical applications. The fabrication of hybrid erythrocyte liposomes is presented by doping red blood cell membranes with synthetic lipid molecules of different classes (PC, PS, PG) and different degrees of saturation (14:0, 16:0-18:1). The respective solubility limits are determined, and material properties of the hybrid liposomes are studied by a combination of X-ray diffraction, epi-fluorescent microscopy, dynamic light scattering (DLS), Zeta potential, UV-vis spectroscopy, and Molecular Dynamics (MD) simulations. Membrane thickness and lipid orientation can be tuned through the addition of phosphatidylcholine lipids. The hybrid membranes can be fluorescently labelled by incorporating Texas-red DHPE, and their charge modified by incorporating phosphatidylserine and phosphatidylglycerol. By using fluorescein labeled dextran as an example, it is demonstrated that small molecules can be encapsulated into these hybrid liposomes.
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Affiliation(s)
- Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Matthew J Blacker
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Alexander Kihm
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, ON, L8S 4M1, Canada.,Department of Experimental Physics, Saarland University, 66123, Saarbrücken, Germany
| | - Quinn Pauli
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Kevin Yang
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Sheilan Sinjari
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Mitchell Johnson
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Janos Juhasz
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.,Juravinski Cancer Centre, Department of Medical Physics, Hamilton, ON, L8V 5C2, Canada
| | - Christian Wagner
- Department of Experimental Physics, Saarland University, 66123, Saarbrücken, Germany
| | - Harald D H Stöver
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, ON, L8S 4M1, Canada
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22
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Ahmed R, Akcan M, Khondker A, Rheinstädter MC, Bozelli JC, Epand RM, Huynh V, Wylie RG, Boulton S, Huang J, Verschoor CP, Melacini G. Atomic resolution map of the soluble amyloid beta assembly toxic surfaces. Chem Sci 2019; 10:6072-6082. [PMID: 31360412 PMCID: PMC6585597 DOI: 10.1039/c9sc01331h] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 05/19/2019] [Indexed: 12/11/2022] Open
Abstract
Atomic resolution map of the soluble amyloid beta assembly (Aβn) “toxic surfaces” that facilitate the early pathogenic events in Alzheimer's disease (AD).
Soluble amyloid beta assemblies (Aβn) are neurotoxic and play a central role in the early phases of the pathogenesis cascade leading to Alzheimer's disease. However, the current knowledge about the molecular determinants of Aβn toxicity is at best scant. Here, we comparatively analyze Aβn prepared in the absence or presence of a catechin library that modulates cellular toxicity. By combining solution NMR with dynamic light scattering, fluorescence spectroscopy, electron microscopy, wide-angle X-ray diffraction and cell viability assays, we identify a cluster of unique molecular signatures that distinguish toxic vs. nontoxic Aβ assemblies. These include the exposure of a hydrophobic surface spanning residues 17–28 and the concurrent shielding of the highly charged N-terminus. We show that the combination of these two dichotomous structural transitions promotes the colocalization and insertion of β-sheet rich Aβn into the membrane, compromising membrane integrity. These previously elusive toxic surfaces mapped here provide an unprecedented foundation to establish structure-toxicity relationships of Aβ assemblies.
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Affiliation(s)
- Rashik Ahmed
- Department of Biochemistry and Biomedical Sciences , McMaster University , Hamilton , ON L8S 4M1 , Canada .
| | - Michael Akcan
- Department of Biochemistry and Biomedical Sciences , McMaster University , Hamilton , ON L8S 4M1 , Canada .
| | - Adree Khondker
- Department of Physics and Astronomy , McMaster University , Hamilton , ON L8S 4M1 , Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy , McMaster University , Hamilton , ON L8S 4M1 , Canada
| | - José C Bozelli
- Department of Biochemistry and Biomedical Sciences , McMaster University , Hamilton , ON L8S 4M1 , Canada .
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences , McMaster University , Hamilton , ON L8S 4M1 , Canada .
| | - Vincent Huynh
- Department of Chemistry and Chemical Biology , McMaster University , Hamilton , ON L8S 4M1 , Canada
| | - Ryan G Wylie
- Department of Chemistry and Chemical Biology , McMaster University , Hamilton , ON L8S 4M1 , Canada
| | - Stephen Boulton
- Department of Biochemistry and Biomedical Sciences , McMaster University , Hamilton , ON L8S 4M1 , Canada .
| | - Jinfeng Huang
- Department of Chemistry and Chemical Biology , McMaster University , Hamilton , ON L8S 4M1 , Canada
| | - Chris P Verschoor
- Department of Health Research Methods, Evidence, and Impact (HEI) , McMaster University , Hamilton , ON L8S 4M1 , Canada
| | - Giuseppe Melacini
- Department of Biochemistry and Biomedical Sciences , McMaster University , Hamilton , ON L8S 4M1 , Canada . .,Department of Chemistry and Chemical Biology , McMaster University , Hamilton , ON L8S 4M1 , Canada
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23
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Khondker A, Hub JS, Rheinstädter MC. Steroid-steroid interactions in biological membranes: Cholesterol and cortisone. Chem Phys Lipids 2019; 221:193-197. [PMID: 30951711 DOI: 10.1016/j.chemphyslip.2019.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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: 12/11/2018] [Revised: 03/27/2019] [Accepted: 04/01/2019] [Indexed: 11/17/2022]
Abstract
Steroid flares are common side effects associated with corticosteroid treatment, and have been recently theorized to be a consequence of drug crystallization. It was previously reported that the lipid bilayer can promote crystallization of cortisone at high local concentrations. Here, we studied the effect of cholesterol on this membrane induced cortisone crystallization. By combining x-ray diffraction and Molecular Dynamics simulations we observe that that the presence of cholesterol suppresses cortisone-induced membrane thinning and cortisone transnucleation. Cortisone located in the head-tail interface of the membranes also in the presence of cholesterol. The cholesterol molecules were found to be tilted and displaced towards the bilayer center as function of cortisone concentration, away from their canonical position. Our results show that membrane cholesterol may play an important role in the ability of lipid bilayers to catalyze the formation of corticosteroid crystallites.
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Affiliation(s)
- Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Jochen S Hub
- Theoretical Physics and Center for Biophysics, Saarland University, Saarbrücken, Germany
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada; Origins Institute, McMaster University, Hamilton, Ontario, Canada.
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24
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Schmidt A, Alsop RJ, Rimal R, Lenzig P, Joussen S, Gervasi NN, Khondker A, Gründer S, Rheinstädter MC, Wiemuth D. Modulation of DEG/ENaCs by Amphiphiles Suggests Sensitivity to Membrane Alterations. Biophys J 2019; 114:1321-1335. [PMID: 29590590 DOI: 10.1016/j.bpj.2018.01.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 01/22/2018] [Accepted: 01/26/2018] [Indexed: 12/25/2022] Open
Abstract
The bile acid-sensitive ion channel is activated by amphiphilic substances such as bile acids or artificial detergents via membrane alterations; however, the mechanism of membrane sensitivity of the bile acid-sensitive ion channel is not known. It has also not been systematically investigated whether other members of the degenerin/epithelial Na+ channel (DEG/ENaC) gene family are affected by amphiphilic compounds. Here, we show that DEG/ENaCs ASIC1a, ASIC3, ENaC, and the purinergic receptor P2X2 are modulated by a large number of different, structurally unrelated amphiphilic substances, namely the detergents N-lauroylsarcosine, Triton X-100, and β-octylglucoside; the fenamate flufenamic acid; the antipsychotic drug chlorpromazine; the natural phenol resveratrol; the chili pepper compound capsaicin; the loop diuretic furosemide; and the antiarrythmic agent verapamil. We determined the modification of membrane properties using large-angle x-ray diffraction experiments on model lipid bilayers, revealing that the amphiphilic compounds are positioned in a characteristic fashion either in the lipid tail group region or in the lipid head group region, demonstrating that they perturbed the membrane structure. Collectively, our results show that DEG/ENaCs and structurally related P2X receptors are modulated by diverse amphiphilic molecules. Furthermore, they suggest alterations of membrane properties by amphiphilic compounds as a mechanism contributing to modulation.
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Affiliation(s)
- Axel Schmidt
- Institute of Physiology, RWTH Aachen University, Aachen, Germany
| | - Rick J Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Rahul Rimal
- Institute of Physiology, RWTH Aachen University, Aachen, Germany
| | - Pia Lenzig
- Institute of Physiology, RWTH Aachen University, Aachen, Germany
| | - Sylvia Joussen
- Institute of Physiology, RWTH Aachen University, Aachen, Germany
| | - Natalie N Gervasi
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Stefan Gründer
- Institute of Physiology, RWTH Aachen University, Aachen, Germany
| | | | - Dominik Wiemuth
- Institute of Physiology, RWTH Aachen University, Aachen, Germany.
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25
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Nickels JD, Smith MD, Alsop RJ, Himbert S, Yahya A, Cordner D, Zolnierczuk P, Stanley CB, Katsaras J, Cheng X, Rheinstädter MC. Lipid Rafts: Buffers of Cell Membrane Physical Properties. J Phys Chem B 2019; 123:2050-2056. [DOI: 10.1021/acs.jpcb.8b12126] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Jonathan D. Nickels
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Micholas Dean Smith
- Center for Molecular Biophysics, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Department of Biochemistry and Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996, United States
| | - Richard J. Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada
| | - Ahmad Yahya
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Destini Cordner
- Department of Chemical and Environmental Engineering, University of Cincinnati, Cincinnati, Ohio 45221, United States
| | - Piotr Zolnierczuk
- Jülich
Center for Neutron Science, Forschungszentrum Juelich GmbH, Outstation
at SNS, Oak Ridge, Tennessee 37830, United States
| | - Christopher B. Stanley
- Large-Scale Structure Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - John Katsaras
- Large-Scale Structure Group, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
- Shull-Wollen Center, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830, United States
| | - Xiaolin Cheng
- College of Pharmacy, Medicinal Chemistry & Pharmacognosy Division, The Ohio State University, Columbus, Ohio 43210, United States
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26
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Bozelli JC, Jennings W, Black S, Hou YH, Lameire D, Chatha P, Kimura T, Berno B, Khondker A, Rheinstädter MC, Epand RM. Membrane curvature allosterically regulates the phosphatidylinositol cycle, controlling its rate and acyl-chain composition of its lipid intermediates. J Biol Chem 2018; 293:17780-17791. [PMID: 30237168 DOI: 10.1074/jbc.ra118.005293] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [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: 08/10/2018] [Revised: 09/04/2018] [Indexed: 01/17/2023] Open
Abstract
Signaling events at membranes are often mediated by membrane lipid composition or membrane physical properties. These membrane properties could act either by favoring the membrane binding of downstream effectors or by modulating their activity. Several proteins can sense/generate membrane physical curvature (i.e. shape). However, the modulation of the activity of enzymes by a membrane's shape has not yet been reported. Here, using a cell-free assay with purified diacylglycerol kinase ϵ (DGKϵ) and liposomes, we studied the activity and acyl-chain specificity of an enzyme of the phosphatidylinositol (PI) cycle, DGKϵ. By systematically varying the model membrane lipid composition and physical properties, we found that DGKϵ has low activity and lacks acyl-chain specificity in locally flat membranes, regardless of the lipid composition. On the other hand, these enzyme properties were greatly enhanced in membrane structures with a negative Gaussian curvature. We also found that this is not a consequence of preferential binding of the enzyme to those structures, but rather is due to a curvature-mediated allosteric regulation of DGKϵ activity and acyl-chain specificity. Moreover, in a fine-tuned interplay between the enzyme and the membrane, DGKϵ favored the formation of structures with greater Gaussian curvature. DGKϵ does not bear a regulatory domain, and these findings reveal the importance of membrane curvature in regulating DGKϵ activity and acyl-chain specificity. Hence, this study highlights that a hierarchic coupling of membrane physical property and lipid composition synergistically regulates membrane signaling events. We propose that this regulatory mechanism of membrane-associated enzyme activity is likely more common than is currently appreciated.
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Affiliation(s)
- José Carlos Bozelli
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - William Jennings
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Stephanie Black
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Yu Heng Hou
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Darius Lameire
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Preet Chatha
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | - Tomohiro Kimura
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1
| | | | - Adree Khondker
- Physics and Astronomy; Origins Institute, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Maikel C Rheinstädter
- Physics and Astronomy; Origins Institute, McMaster University, Hamilton, Ontario L8S 4L8, Canada
| | - Richard M Epand
- From the Department of Biochemistry and Biomedical Sciences, Health Sciences Centre, McMaster University, Hamilton, Ontario L8S 4K1; Departments of Chemistry.
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27
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Khondker A, Alsop RJ, Himbert S, Tang J, Shi AC, Hitchcock AP, Rheinstädter MC. Membrane-Modulating Drugs can Affect the Size of Amyloid-β 25-35 Aggregates in Anionic Membranes. Sci Rep 2018; 8:12367. [PMID: 30120270 PMCID: PMC6098001 DOI: 10.1038/s41598-018-30431-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 07/30/2018] [Indexed: 01/08/2023] Open
Abstract
The formation of amyloid-β plaques is one of the hallmarks of Alzheimer's disease. The presence of an amphiphatic cell membrane can accelerate the formation of amyloid-β aggregates, making it a potential druggable target to delay the progression of Alzheimer's disease. We have prepared unsaturated anionic membranes made of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) and 1,2-dimyristoyl-sn-glycero-3-phospho-L-serine (DMPS) and added the trans-membrane segment Aβ25-35. Peptide plaques spontaneously form in these membranes at high peptide concentrations of 20 mol%, which show the characteristic cross-β motif (concentrations are relative to the number of membrane lipids and indicate the peptide-to-lipid ratio). We used atomic force microscopy, fluorescence microscopy, x-ray microscopy, x-ray diffraction, UV-vis spectroscopy and Molecular Dynamics (MD) simulations to study three membrane-active molecules which have been speculated to have an effect in Alzheimer's disease: melatonin, acetylsalicyclic acid (ASA) and curcumin at concentrations of 5 mol% (drug-to-peptide ratio). Melatonin did not change the structural parameters of the membranes and did not impact the size or extent of peptide clusters. While ASA led to a membrane thickening and stiffening, curcumin made membranes softer and thinner. As a result, ASA was found to lead to the formation of larger peptide aggregates, whereas curcumin reduced the volume fraction of cross-β sheets by ~70%. We speculate that the interface between membrane and peptide cluster becomes less favorable in thick and stiff membranes, which favors the formation of larger aggregates, while the corresponding energy mismatch is reduced in soft and thin membranes. Our results present evidence that cross-β sheets of Aβ25-35 in anionic unsaturated lipid membranes can be re-dissolved by changing membrane properties to reduce domain mismatch.
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Affiliation(s)
- Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Richard J Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - Jennifer Tang
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.,Origins Institute, McMaster University, Hamilton, Ontario, Canada
| | - An-Chang Shi
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Adam P Hitchcock
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada. .,Origins Institute, McMaster University, Hamilton, Ontario, Canada.
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28
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Abstract
Carbapenems are broad-spectrum antibiotics used today to treat otherwise antibiotic resistant bacteria. As their target transpeptidase is located within the periplasm of the Gram-negative bacteria, they can participate in nonspecific interactions between the inner leaflet of the outer membrane and the outer leaflet of the inner membrane. We, therefore, studied the interaction of the four most clinically relevant carbapenems, namely, imipenem, doripenem, ertapenem, and meropenem, with model phospholipid bilayers made of 1,2-dimyristoyl- sn-glycero-3-phosphocholine (DMPC) using molecular dynamics (MD) simulations and X-ray diffraction at low and high concentration of the drugs corresponding to 1 and 8 mol % (with respect to the number of membrane lipids). Membrane solubility was found to decrease from imipenem to doripenem, ertapenem, and finally meropenem. At low concentrations, membrane insertion was found to be a two step process, where the drugs first adsorb to the lipid head groups before inserting through a rotation of the molecule. At higher drug concentrations, the molecules were found to form aggregates in the aqueous phase before making contact with the membranes and spontaneously inserting into the bilayers. Two populations of imipenem were found: in the headgroup at ∼17 Å from the bilayer center and an inserted population at z-values of about 7 Å. Other carbapenems were found to localize in the tail groups with meropenem at ∼10 Å, doripenem at ∼8 Å, and ertapenem at ∼8 Å. The observed membrane solubility of carbapenems can potentially impact the availability of the drug to the target penicillin-binding proteins, potentially affecting their clinical efficacy.
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Affiliation(s)
- Adree Khondker
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Dylan J. Malenfant
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Alexander K. Dhaliwal
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Maikel C. Rheinstädter
- Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada
- Origins Institute, McMaster University, Hamilton, Ontario L8S 4M1, Canada
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29
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Himbert S, Alsop RJ, Rheinstädter MC. The Molecular Structure of Human Red Blood Cell Membranes From Highly Oriented, Solid Supported Multi-Lamellar Membranes. Biophys J 2018. [DOI: 10.1016/j.bpj.2017.11.1562] [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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30
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Alsop RJ, Himbert S, Dhaliwal A, Schmalzl K, Rheinstädter MC. Aspirin locally disrupts the liquid-ordered phase. R Soc Open Sci 2018; 5:171710. [PMID: 29515878 PMCID: PMC5830767 DOI: 10.1098/rsos.171710] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2017] [Accepted: 01/23/2018] [Indexed: 06/12/2023]
Abstract
Local structure and dynamics of lipid membranes play an important role in membrane function. The diffusion of small molecules, the curvature of lipids around a protein and the existence of cholesterol-rich lipid domains (rafts) are examples for the membrane to serve as a functional interface. The collective fluctuations of lipid tails, in particular, are relevant for diffusion of membrane constituents and small molecules in and across membranes, and for structure and formation of membrane domains. We studied the effect of aspirin (acetylsalicylic acid, ASA) on local structure and dynamics of membranes composed of dimyristoylphosphocholine (DMPC) and cholesterol. Aspirin is a common analgesic, but is also used in the treatment of cholesterol. Using coherent inelastic neutron scattering experiments and molecular dynamics (MD) simulations, we present evidence that ASA binds to liquid-ordered, raft-like domains and disturbs domain organization and dampens collective fluctuations. By hydrogen-bonding to lipid molecules, ASA forms 'superfluid' complexes with lipid molecules that can organize laterally in superlattices and suppress cholesterol's ordering effect.
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Affiliation(s)
- Richard J. Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Alexander Dhaliwal
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Karin Schmalzl
- JCNS, Forschungszentrum Jülich GmbH, Jülich Centre for Neutron Science at ILL, Grenoble, France
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31
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Mueller E, Alsop RJ, Scotti A, Bleuel M, Rheinstädter MC, Richtering W, Hoare T. Dynamically Cross-Linked Self-Assembled Thermoresponsive Microgels with Homogeneous Internal Structures. Langmuir 2018; 34:1601-1612. [PMID: 29261314 DOI: 10.1021/acs.langmuir.7b03664] [Citation(s) in RCA: 18] [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: 06/07/2023]
Abstract
The internal morphology of temperature-responsive degradable poly(N-isopropylacrylamide) (PNIPAM) microgels formed via an aqueous self-assembly process based on hydrazide and aldehyde-functionalized PNIPAM oligomers is investigated. A combination of surface force measurements, small angle neutron scattering (SANS), and ultrasmall angle neutron scattering (USANS) was used to demonstrate that the self-assembled microgels have a homogeneously cross-linked internal structure. This result is surprising given the sequential addition process used to fabricate the microgels, which was expected to result in a densely cross-linked shell-diffuse core structure. The homogeneous internal structure identified is also significantly different than conventional microgels prepared via precipitation polymerization, which typically exhibit a diffuse shell-dense core structure. The homogeneous structure is hypothesized to result from the dynamic nature of the hydrazone cross-linking chemistry used to couple with the assembly conditions chosen that promote polymer interdiffusion. The lack of an internal cross-linking gradient within these degradable and monodisperse microgels is expected to facilitate more consistent drug release over time, improved optical properties, and other potential application benefits.
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Affiliation(s)
- Eva Mueller
- Department of Chemical Engineering, McMaster University , 1280 Main Street W, Hamilton, Ontario L8S 4L7, Canada
| | - Richard J Alsop
- Department of Physics and Astronomy, McMaster University , 1280 Main Street W, Hamilton, Ontario L8S 4M1, Canada
| | - Andrea Scotti
- Department of Physical Chemistry (IPC), RWTH Aachen , Landoltweg 2, 52074 Aachen, Germany
| | - Markus Bleuel
- Neutron-Condensed Matter Science Group, National Institute of Standards and Technology (NIST) , 100 Bureau Drive, Gaithersburg, Maryland 20899, United States
- Department of Materials Science and Engineering, University of Maryland , College Park, Maryland 20742-2115, United States
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University , 1280 Main Street W, Hamilton, Ontario L8S 4M1, Canada
| | - Walter Richtering
- Department of Physical Chemistry (IPC), RWTH Aachen , Landoltweg 2, 52074 Aachen, Germany
| | - Todd Hoare
- Department of Chemical Engineering, McMaster University , 1280 Main Street W, Hamilton, Ontario L8S 4L7, Canada
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32
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Soomro A, Alsop RJ, Negishi A, Kreplak L, Fudge D, Kuczmarski ER, Goldman RD, Rheinstädter MC. Giant axonal neuropathy alters the structure of keratin intermediate filaments in human hair. J R Soc Interface 2017; 14:rsif.2017.0123. [PMID: 28424304 DOI: 10.1098/rsif.2017.0123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [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: 02/18/2017] [Accepted: 03/24/2017] [Indexed: 11/12/2022] Open
Abstract
Giant axonal neuropathy (GAN) follows an autosomal recessive genetic inheritance and impedes the peripheral and central nervous system due to axonal swellings that are packed with neurofilaments. The patients display a number of phenotypes, including hypotonia, muscle weakness, decreased reflexes, ataxia, seizures, intellectual disability, pale skin and often curled hair. We used X-ray diffraction and tensile testing to determine potential changes to the structure of keratin intermediate filaments (IFs) in the hair of patients with GAN. A statistically significant decrease in the 47 and the 27 Å diffraction signals were observed. Tensile tests determined that the hair was slightly stiffer, stronger and more extensible in GAN patients. These results suggest that the structure of keratin IFs in hair is altered in GAN, and the findings are compatible with an increased positional disorder of the keratin tetramers within the hair fibres.
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Affiliation(s)
- Asfia Soomro
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Richard J Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Atsuko Negishi
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Laurent Kreplak
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Douglas Fudge
- Department of Integrative Biology, University of Guelph, Guelph, Ontario, Canada
| | - Edward R Kuczmarski
- Department of Cell and Molecular Biology, Northwestern University, Chicago, IL, USA
| | - Robert D Goldman
- Department of Cell and Molecular Biology, Northwestern University, Chicago, IL, USA
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33
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Gilbert T, Alsop RJ, Babi M, Moran-Mirabal J, Rheinstädter MC, Hoare T. Nanostructure of Fully Injectable Hydrazone-Thiosuccinimide Interpenetrating Polymer Network Hydrogels Assessed by Small-Angle Neutron Scattering and dSTORM Single-Molecule Fluorescence Microscopy. ACS Appl Mater Interfaces 2017; 9:42179-42191. [PMID: 29131571 DOI: 10.1021/acsami.7b11637] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Herein, we comprehensively investigate the internal morphology of fully injectable interpenetrating networks (IPNs) prepared via coextrusion of functionalized precursor polymer solutions based on thermoresponsive poly(N-isopropylacrylamide) (PNIPAM) and nonthermoresponsive poly(vinyl pyrrolidone) (PVP) by reactive mixing using kinetically orthogonal hydrazone and thiosuccinimide cross-linking mechanisms. Small-angle neutron scattering, probing both the full IPN as well as the individual constituent networks of the IPN using index-matching, suggests a partially mixed internal structure characterized by PNIPAM-rich domains entrapped in a clustered PVP-rich phase. This interpretation is supported by super-resolution fluorescence microscopy (direct stochastic optical reconstruction microscopy) measurements on the same gels on a different length scale, which show both the overall phase segregation typical of an IPN as well as moderate mixing of PNIPAM into the PVP-rich phase. Such a morphology is consistent with the kinetics of both gelation and phase separation in this in situ gelling system, in which gelation effectively traps a fraction of the PNIPAM in the PVP phase prior to full phase separation; by contrast, such interphase mixing is not observed in semi-IPN control hydrogels. This knowledge has significant potential for the design of an injectable hydrogel with internal morphologies optimized for particular biomedical applications.
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Affiliation(s)
- Trevor Gilbert
- Department of Chemical Engineering, McMaster University , 1280 Main St. W, Hamilton, Ontario L8S 4L7, Canada
| | | | | | | | | | - Todd Hoare
- Department of Chemical Engineering, McMaster University , 1280 Main St. W, Hamilton, Ontario L8S 4L7, Canada
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34
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Khondker A, Alsop RJ, Dhaliwal A, Saem S, Moran-Mirabal JM, Rheinstädter MC. Membrane Cholesterol Reduces Polymyxin B Nephrotoxicity in Renal Membrane Analogs. Biophys J 2017; 113:2016-2028. [PMID: 29117525 DOI: 10.1016/j.bpj.2017.09.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Revised: 08/17/2017] [Accepted: 09/13/2017] [Indexed: 01/21/2023] Open
Abstract
Polymyxin B (PmB) is a "last-line" antibiotic scarcely used due to its nephrotoxicity. However, the molecular basis for antibiotic nephrotoxicity is not clearly understood. We prepared kidney membrane analogs of detergent-susceptible membranes, depleted of cholesterol, and cholesterol enriched, resistant membranes. In both analogs, PmB led to membrane damage. By combining x-ray diffraction, molecular dynamics simulations, and electrochemistry, we present evidence for two populations of PmB molecules: peptides that lie flat on the membranes, and an inserted state. In cholesterol depleted membranes, PmB forms clusters on the membranes leading to an indentation of the bilayers and increase in water permeation. The inserted peptides formed aggregates in the membrane core leading to further structural instabilities and increased water intake. The presence of cholesterol in the resistant membrane analogs led to a significant decrease in membrane damage. Although cholesterol did not inhibit peptide insertion, it minimized peptide clustering and water intake through stabilization of the bilayer structure and suppression of lipid and peptide mobility.
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Affiliation(s)
- Adree Khondker
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Richard J Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Alexander Dhaliwal
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada
| | - Sokunthearath Saem
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
| | - Jose M Moran-Mirabal
- Department of Chemistry and Chemical Biology, McMaster University, Hamilton, Ontario, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.
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35
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Bakaic E, Smeets NMB, Barrigar O, Alsop R, Rheinstädter MC, Hoare T. pH-Ionizable in Situ Gelling Poly(oligo ethylene glycol methacrylate)-Based Hydrogels: The Role of Internal Network Structures in Controlling Macroscopic Properties. Macromolecules 2017. [DOI: 10.1021/acs.macromol.7b01505] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Emilia Bakaic
- Department
of Chemical Engineering and ‡Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8
| | - Niels M. B. Smeets
- Department
of Chemical Engineering and ‡Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8
| | - Owen Barrigar
- Department
of Chemical Engineering and ‡Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8
| | - Richard Alsop
- Department
of Chemical Engineering and ‡Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8
| | - Maikel C. Rheinstädter
- Department
of Chemical Engineering and ‡Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8
| | - Todd Hoare
- Department
of Chemical Engineering and ‡Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8
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36
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Abstract
Curcumin is the main ingredient in turmeric, a common Indian spice. Curcumin shows a broad spectrum of effects, including anti-Alzheimer's and antioxidant properties. An interaction between curcumin and lipid membranes has been speculated as the root cause of this activity, and the molecule is often proposed to protect the bilayer. However, the detailed molecular mechanism of this protection is disputed. There is evidence that curcumin either (a) lies flat on the bilayer and provides a "carpet" for protection by forming a steric barrier, or (b) inserts into the membrane and stiffens tails, thereby protecting against peptide insertion. We studied the interaction between curcumin and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) bilayers at different concentrations using high-resolution X-ray diffraction and molecular dynamics (MD) computer simulations. We observed curcumin molecules forming a carpet in dehydrated bilayers, whereas in hydrated membranes the curcumin molecules were found to insert into the bilayers. From calculations of the potential of mean force (PMF), we find two minima, a metastable state in the headgroup region, at |z| ≈ 22 Å, and a global minimum in the hydrophobic membrane core, at |z| ≈ 9 Å. The population of the two states depends on membrane hydration. Experiments may thus observe curcumin in a carpet or inserted position, depending on the osmotic pressure conditions created, for instance, by salts, buffer solutions, substrates, or macromolecular solutes. In the carpet model, curcumin dehydrates lipid bilayers and decreases fluidity. When inserted, curcumin leads to a further fluidification of the membranes and an increase in tail fluctuations, contrary to cholesterol's condensing effect.
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Affiliation(s)
- Richard J Alsop
- Department of Physics and Astronomy, McMaster University , Hamilton, Ontario L8S 4M1, Canada
| | - Alexander Dhaliwal
- Department of Physics and Astronomy, McMaster University , Hamilton, Ontario L8S 4M1, Canada
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University , Hamilton, Ontario L8S 4M1, Canada
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37
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Gill U, Sutherland T, Himbert S, Zhu Y, Rheinstädter MC, Cranston ED, Moran-Mirabal JM. Beyond buckling: humidity-independent measurement of the mechanical properties of green nanobiocomposite films. Nanoscale 2017; 9:7781-7790. [PMID: 28397935 DOI: 10.1039/c7nr00251c] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Precise knowledge of the mechanical properties of emerging nanomaterials and nanocomposites is crucial to match their performance with suitable applications. While methods to characterize mechanical properties exist, they are limited by instrument sensitivity and sample requirements. For bio-based nanomaterials this challenge is exacerbated by the extreme dependence of mechanical properties on humidity. This work presents an alternative approach, based on polymer shrinking-induced wrinkling mechanics, to determine the elastic modulus of nanobiocomposite films in a humidity-independent manner. Layer-by-layer (LbL) films containing cellulose nanocrystals (CNCs) and water-soluble polymers were deposited onto pre-stressed polystyrene substrates followed by thermal shrinking, which wrinkled the films to give them characteristic topographies. Three deposition parameters were varied during LbL assembly: (1) polymer type (xyloglucan - XG, or polyethyleneimine - PEI); (2) polymer concentration (0.1 or 1 wt%); and (3) number of deposition cycles, resulting in 10-600 nm thick nanobiocomposite films with tuneable compositions. Fast Fourier transform analysis on electron microscopy images of the wrinkled films was used to calculate humidity-independent moduli of 70 ± 2 GPa for CNC-XG0.1, 72 ± 2 GPa for CNC-PEI0.1, and 32.2 ± 0.8 GPa for CNC-PEI1.0 films. This structuring method is straightforward and amenable to a wide range of supported thin films.
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Affiliation(s)
- Urooj Gill
- Department of Chemistry and Chemical Biology, McMaster University, 1280 Main St. W., Hamilton, ON, CanadaL8S 4M1.
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38
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Shao S, Do TN, Razi A, Chitgupi U, Geng J, Alsop RJ, Dzikovski BG, Rheinstädter MC, Ortega J, Karttunen M, Spernyak JA, Lovell JF. Design of Hydrated Porphyrin-Phospholipid Bilayers with Enhanced Magnetic Resonance Contrast. Small 2017; 13:10.1002/smll.201602505. [PMID: 27739249 PMCID: PMC5209247 DOI: 10.1002/smll.201602505] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2016] [Revised: 08/30/2016] [Indexed: 05/29/2023]
Abstract
Computer simulations are used to design more hydrated bilayers, formed from amine-modified porphyrin-phospholipids (PoPs). Experiments confirm that the new constructs give rise to bilayers with greater water content. When chelated with manganese, amine-modified PoPs provide improved contrast for magnetic resonance and are safely used for imaging in vivo.
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Affiliation(s)
- Shuai Shao
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
| | - Trang Nhu Do
- Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L3G1, Canada
| | - Aida Razi
- Department of Biochemistry and Biomedical Sciences and M. G. DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, Ontario L8S4L8, Canada
| | - Upendra Chitgupi
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
| | - Jumin Geng
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
| | - Richard J. Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S4M1, Canada
| | - Boris G. Dzikovski
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S4M1, Canada
| | - Joaquin Ortega
- Department of Biochemistry and Biomedical Sciences and M. G. DeGroote Institute for Infectious Diseases Research, McMaster University, Hamilton, Ontario L8S4L8, Canada
| | - Mikko Karttunen
- Department of Chemistry and Waterloo Institute for Nanotechnology, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L3G1, Canada. Department of Mathematics and Computer Science & Institute for Complex Molecular Systems, Eindhoven University of Technology, Eindhoven, Netherlands
| | - Joseph A. Spernyak
- Department of Cell Stress Biology, Roswell Park Cancer Institute Buffalo, NY 14263, USA
| | - Jonathan F. Lovell
- Department of Biomedical Engineering, University at Buffalo, State University of New York, Buffalo, New York 14260, USA
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39
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Khondker A, Dhaliwal A, Alsop RJ, Tang J, Backholm M, Shi AC, Rheinstädter MC. Partitioning of caffeine in lipid bilayers reduces membrane fluidity and increases membrane thickness. Phys Chem Chem Phys 2017; 19:7101-7111. [DOI: 10.1039/c6cp08104e] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Caffeine partitions in lipid membranes in the head to tail interface and leads to a thickening and defluidification.
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Affiliation(s)
- Adree Khondker
- Department of Physics and Astronomy
- McMaster University
- Hamilton
- Canada
| | | | - Richard J. Alsop
- Department of Physics and Astronomy
- McMaster University
- Hamilton
- Canada
| | - Jennifer Tang
- Department of Physics and Astronomy
- McMaster University
- Hamilton
- Canada
| | - Matilda Backholm
- Department of Physics and Astronomy
- McMaster University
- Hamilton
- Canada
- Department of Applied Physics
| | - An-Chang Shi
- Department of Physics and Astronomy
- McMaster University
- Hamilton
- Canada
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40
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Schmidt A, Löhrer D, Alsop RJ, Lenzig P, Oslender-Bujotzek A, Wirtz M, Rheinstädter MC, Gründer S, Wiemuth D. A Cytosolic Amphiphilic α-Helix Controls the Activity of the Bile Acid-sensitive Ion Channel (BASIC). J Biol Chem 2016; 291:24551-24565. [PMID: 27679529 DOI: 10.1074/jbc.m116.756437] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [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: 08/31/2016] [Revised: 09/19/2016] [Indexed: 12/22/2022] Open
Abstract
The bile acid-sensitive ion channel (BASIC) is a member of the degenerin/epithelial Na+ channel (Deg/ENaC) family of ion channels. It is mainly found in bile duct epithelial cells, the intestinal tract, and the cerebellum and is activated by alterations of its membrane environment. Bile acids, one class of putative physiological activators, exert their effect by changing membrane properties, leading to an opening of the channel. The physiological function of BASIC, however, is unknown. Deg/ENaC channels are characterized by a trimeric subunit composition. Each subunit is composed of two transmembrane segments, which are linked by a large extracellular domain. The termini of the channels protrude into the cytosol. Many Deg/ENaC channels contain regulatory domains and sequence motifs within their cytosolic domains. In this study, we show that BASIC contains an amphiphilic α-helical structure within its N-terminal domain. This α-helix binds to the cytosolic face of the plasma membrane and stabilizes a closed state. Truncation of this domain renders the channel hyperactive. Collectively, we identify a cytoplasmic domain, unique to BASIC, that controls channel activity via membrane interaction.
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Affiliation(s)
- Axel Schmidt
- From the Institute of Physiology, RWTH Aachen University, D-52074 Aachen, Germany and
| | - Daniel Löhrer
- From the Institute of Physiology, RWTH Aachen University, D-52074 Aachen, Germany and
| | - Richard J Alsop
- the Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Pia Lenzig
- From the Institute of Physiology, RWTH Aachen University, D-52074 Aachen, Germany and
| | | | - Monika Wirtz
- From the Institute of Physiology, RWTH Aachen University, D-52074 Aachen, Germany and
| | - Maikel C Rheinstädter
- the Department of Physics and Astronomy, McMaster University, Hamilton, Ontario L8S 4M1, Canada
| | - Stefan Gründer
- From the Institute of Physiology, RWTH Aachen University, D-52074 Aachen, Germany and
| | - Dominik Wiemuth
- From the Institute of Physiology, RWTH Aachen University, D-52074 Aachen, Germany and.
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41
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Himbert S, Chapman M, Deamer DW, Rheinstädter MC. Organization of Nucleotides in Different Environments and the Formation of Pre-Polymers. Sci Rep 2016; 6:31285. [PMID: 27545761 PMCID: PMC4992878 DOI: 10.1038/srep31285] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/15/2016] [Indexed: 11/19/2022] Open
Abstract
RNA is a linear polymer of nucleotides linked by a ribose-phosphate backbone. Polymerization of nucleotides occurs in a condensation reaction in which phosphodiester bonds are formed. However, in the absence of enzymes and metabolism there has been no obvious way for RNA-like molecules to be produced and then encapsulated in cellular compartments. We investigated 5′-adenosine monophosphate (AMP) and 5′-uridine monophosphate (UMP) molecules confined in multi-lamellar phospholipid bilayers, nanoscopic films, ammonium chloride salt crystals and Montmorillonite clay, previously proposed to promote polymerization. X-ray diffraction was used to determine whether such conditions imposed a degree of order on the nucleotides. Two nucleotide signals were observed in all matrices, one corresponding to a nearest neighbour distance of 4.6 Å attributed to nucleotides that form a disordered, glassy structure. A second, smaller distance of 3.4 Å agrees well with the distance between stacked base pairs in the RNA backbone, and was assigned to the formation of pre-polymers, i.e., the organization of nucleotides into stacks of about 10 monomers. Such ordering can provide conditions that promote the nonenzymatic polymerization of RNA strands under prebiotic conditions. Experiments were modeled by Monte-Carlo simulations, which provide details of the molecular structure of these pre-polymers.
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Affiliation(s)
- Sebastian Himbert
- Department of Physics and Astronomy, McMaster University, Hamilton, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, L8S 4M1, Canada.,Department of Experimental Physics, Saarland University, 66123 Saarbrücken, Germany
| | - Mindy Chapman
- Department of Physics and Astronomy, McMaster University, Hamilton, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, L8S 4M1, Canada
| | - David W Deamer
- Department of Biomolecular Engineering, University of California, Santa Cruz, 95064, USA
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, L8S 4M1, Canada.,Origins Institute, McMaster University, Hamilton, L8S 4M1, Canada
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42
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Alsop RJ, Maria Schober R, Rheinstädter MC. Swelling of phospholipid membranes by divalent metal ions depends on the location of the ions in the bilayers. Soft Matter 2016; 12:6737-6748. [PMID: 27453289 DOI: 10.1039/c6sm00695g] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
The Hofmeister series illustrates how salts produce a wide range of effects in biological systems, which are not exclusively explained by ion charge. In lipid membranes, charged ions have been shown to bind to lipids and either hydrate or dehydrate lipid head groups, and also to swell the water layer in multi-lamellar systems. Typically, Hofmeister phenomena are explained by the interaction of the ions with water, as well as with biological interfaces, such as proteins or membranes. We studied the effect of the divalent cations Mg(2+), Ca(2+), Fe(2+), and Zn(2+) on oriented, stacked, phospholipid bilayers made of dimyristoylphosphatidylcholine (DMPC). Using high-resolution X-ray diffraction, we observed that the cations lead to a swelling of the water layer between the bilayers, without causing significant changes to the bilayer structure. The cations swelled the bilayers in different amounts, in the order Fe(2+) > Mg(2+) > Ca(2+) > Zn(2+). By decomposing the total bilayer electron density into different molecular groups, Zn(2+) and Ca(2+) were found to interact with the glycerol groups of the lipid molecules and cause minor swelling of the bilayers. Mg(2+) and Fe(2+) were found to position near the phosphate groups and cause a strong increase in the number of hydration water molecules. Our results present a molecular mechanism-of-action for the Hofmeister series in phospholipid membranes.
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Affiliation(s)
- Richard J Alsop
- Department of Physics and Astronomy, McMaster University, ABB-241, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
| | - Rafaëla Maria Schober
- Department of Physics and Astronomy, McMaster University, ABB-241, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, ABB-241, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
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43
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Tang J, Alsop RJ, Backholm M, Dies H, Shi AC, Rheinstädter MC. Amyloid-β(25-35) peptides aggregate into cross-β sheets in unsaturated anionic lipid membranes at high peptide concentrations. Soft Matter 2016; 12:3165-3176. [PMID: 26934592 DOI: 10.1039/c5sm02619a] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
One of the hallmarks of Alzheimer's disease is the formation of protein plaques in the brain, which mainly consist of amyloid-β peptides of different lengths. While the role of these plaques in the pathology of the disease is not clear, the mechanism behind peptide aggregation is a topic of intense research and discussion. Because of their simplicity, synthetic membranes are promising model systems to identify the elementary processes involved. We prepared unsaturated zwitterionic/anionic lipid membranes made of 1-palmitoyl-2-oleoyl-sn-glycero-phosphocholine (POPC) and 1,2-dimyristoyl-sn-glycero-3-phospho-l-serine (DMPS) at concentrations of POPC/3 mol% DMPS containing 0 mol%, 3 mol%, 10 mol%, and 20 mol% amyloid-β25-35 peptides. Membrane-embedded peptide clusters were observed at peptide concentrations of 10 and 20 mol% with a typical cluster size of ∼11 μm. Cluster density increased with peptide concentration from 59 (±3) clusters per mm(2) to 920 (±64) clusters per mm(2), respectively. While monomeric peptides take an α-helical state when embedded in lipid bilayers at low peptide concentrations, the peptides in peptide clusters were found to form cross-β sheets and showed the characteristic pattern in X-ray experiments. The presence of the peptides was accompanied by an elastic distortion of the bilayers, which can induce a long range interaction between the peptides. The experimentally observed cluster patterns agree well with Monte Carlo simulations of long-range interacting peptides. This interaction may be the fundamental process behind cross-β sheet formation in membranes and these sheets may serve as seeds for further growth into amyloid fibrils.
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Affiliation(s)
- Jennifer Tang
- Department of Physics and Astronomy, McMaster University, ABB-241, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
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44
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Urosev I, Bakaic E, Alsop RJ, Rheinstädter MC, Hoare T. Tuning the properties of injectable poly(oligoethylene glycol methacrylate) hydrogels by controlling precursor polymer molecular weight. J Mater Chem B 2016; 4:6541-6551. [DOI: 10.1039/c6tb02197b] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The properties of POEGMA hydrogels are tuned in a chemistry-independent manner via manipulation of the molecular weight of precursor polymers.
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Affiliation(s)
- Ivan Urosev
- School of Biomedical Engineering
- McMaster University
- Hamilton
- Canada
| | - Emilia Bakaic
- Department of Chemical Engineering
- McMaster University
- Hamilton
- Canada
| | - Richard J. Alsop
- Department of Physics and Astronomy
- McMaster University
- Hamilton
- Canada
| | | | - Todd Hoare
- School of Biomedical Engineering
- McMaster University
- Hamilton
- Canada
- Department of Chemical Engineering
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45
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Barrett MA, Alsop RJ, Hauß T, Rheinstädter MC. The Position of Aβ22-40 and Aβ1-42 in Anionic Lipid Membranes Containing Cholesterol. Membranes (Basel) 2015; 5:824-43. [PMID: 26633529 PMCID: PMC4704014 DOI: 10.3390/membranes5040824] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2015] [Accepted: 11/25/2015] [Indexed: 02/07/2023]
Abstract
Amyloid-β peptides interact with cell membranes in the human brain and are associated with neurodegenerative diseases, such as Alzheimer's disease. An emerging explanation of the molecular mechanism, which results in neurodegeneration, places the cause of neurotoxicity of the amyloid- peptides on their potentially negative interaction with neuronal membranes. It is known that amyloid-β peptides interact with the membrane, modifying the membrane's structural and dynamic properties. We present a series of X-ray diffraction experiments on anionic model lipid membranes containing various amounts of cholesterol. These experiments provide experimental evidence for an interaction of both the full length amyloid-β1-42 peptide, and the peptide fragment amyloid-β22-40 with anionic bilayer containing cholesterol. The location of the amyloid-β peptides was determined from these experiments, with the full length peptide embedding into the membrane, and the peptide fragment occupying 2 positions-on the membrane surface and embedded into the membrane core.
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Affiliation(s)
- Matthew A Barrett
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Lise-Meitner-Campus, Berlin, Germany.
| | - Richard J Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada.
| | - Thomas Hauß
- Soft Matter and Functional Materials, Helmholtz-Zentrum Berlin für Materialien und Energie, Lise-Meitner-Campus, Berlin, Germany.
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON L8S 4M1, Canada.
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Toppozini L, Roosen-Runge F, Bewley RI, Dalgliesh RM, Perring T, Seydel T, Glyde HR, García Sakai V, Rheinstädter MC. Anomalous and anisotropic nanoscale diffusion of hydration water molecules in fluid lipid membranes. Soft Matter 2015; 11:8354-8371. [PMID: 26338138 DOI: 10.1039/c5sm01713k] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
We have studied nanoscale diffusion of membrane hydration water in fluid-phase lipid bilayers made of 1,2-dimyristoyl-3-phosphocholine (DMPC) using incoherent quasi-elastic neutron scattering. Dynamics were fit directly in the energy domain using the Fourier transform of a stretched exponential. By using large, 2-dimensional detectors, lateral motions of water molecules and motions perpendicular to the membranes could be studied simultaneously, resulting in 2-dimensional maps of relaxation time, τ, and stretching exponent, β. We present experimental evidence for anomalous (sub-diffusive) and anisotropic diffusion of membrane hydration water molecules over nanometer distances. By combining molecular dynamics and Brownian dynamics simulations, the potential microscopic origins for the anomaly and anisotropy of hydration water were investigated. Bulk water was found to show intrinsic sub-diffusive motion at time scales of several picoseconds, likely related to caging effects. In membrane hydration water, however, the anisotropy of confinement and local dynamical environments leads to an anisotropy of relaxation times and stretched exponents, indicative of anomalous dynamics.
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Affiliation(s)
- Laura Toppozini
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.
| | | | | | | | - Toby Perring
- ISIS, Rutherford Appleton Laboratory, Didcot, UK
| | | | - Henry R Glyde
- Department of Physics and Astronomy, University of Delaware, Newark, Delaware, USA
| | | | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, Canada.
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47
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Zhang Y, Alsop RJ, Soomro A, Yang FC, Rheinstädter MC. Effect of shampoo, conditioner and permanent waving on the molecular structure of human hair. PeerJ 2015; 3:e1296. [PMID: 26557428 PMCID: PMC4636411 DOI: 10.7717/peerj.1296] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 09/15/2015] [Indexed: 11/28/2022] Open
Abstract
The hair is a filamentous biomaterial consisting of the cuticle, the cortex and the medulla, all held together by the cell membrane complex. The cortex mostly consists of helical keratin proteins that spiral together to form coiled-coil dimers, intermediate filaments, micro-fibrils and macro-fibrils. We used X-ray diffraction to study hair structure on the molecular level, at length scales between ∼3–90 Å, in hopes of developing a diagnostic method for diseases affecting hair structure allowing for fast and noninvasive screening. However, such an approach can only be successful if common hair treatments do not affect molecular hair structure. We found that a single use of shampoo and conditioner has no effect on packing of keratin molecules, structure of the intermediate filaments or internal lipid composition of the membrane complex. Permanent waving treatments are known to break and reform disulfide linkages in the hair. Single application of a perming product was found to deeply penetrate the hair and reduce the number of keratin coiled-coils and change the structure of the intermediate filaments. Signals related to the coiled-coil structure of the α-keratin molecules at 5 and 9.5 Å were found to be decreased while a signal associated with the organization of the intermediate filaments at 47 Å was significantly elevated in permed hair. Both these observations are related to breaking of the bonds between two coiled-coil keratin dimers.
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Affiliation(s)
- Yuchen Zhang
- Department of Physics & Astronomy, McMaster University , Hamilton, ON , Canada
| | - Richard J Alsop
- Department of Physics & Astronomy, McMaster University , Hamilton, ON , Canada
| | - Asfia Soomro
- Department of Physics & Astronomy, McMaster University , Hamilton, ON , Canada
| | - Fei-Chi Yang
- Department of Physics & Astronomy, McMaster University , Hamilton, ON , Canada
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48
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Tang J, Alsop RJ, Schmalzl K, Epand RM, Rheinstädter MC. Strong Static Magnetic Fields Increase the Gel Signal in Partially Hydrated DPPC/DMPC Membranes. Membranes (Basel) 2015; 5:532-52. [PMID: 26426063 PMCID: PMC4703998 DOI: 10.3390/membranes5040532] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Accepted: 09/17/2015] [Indexed: 11/16/2022]
Abstract
It was recently reported that static magnetic fields increase lipid order in the hydrophobic membrane core of dehydrated native plant plasma membranes [Poinapen, Soft Matter 9:6804-6813, 2013]. As plasma membranes are multicomponent, highly complex structures, in order to elucidate the origin of this effect, we prepared model membranes consisting of a lipid species with low and high melting temperature. By controlling the temperature, bilayers coexisting of small gel and fluid domains were prepared as a basic model for the plasma membrane core. We studied molecular order in mixed lipid membranes made of dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) using neutron diffraction in the presence of strong static magnetic fields up to 3.5 T. The contribution of the hydrophobic membrane core was highlighted through deuterium labeling the lipid acyl chains. There was no observable effect on lipid organization in fluid or gel domains at high hydration of the membranes. However, lipid order was found to be enhanced at a reduced relative humidity of 43%: a magnetic field of 3.5 T led to an increase of the gel signal in the diffraction patterns of 5%. While all biological materials have weak diamagnetic properties, the corresponding energy is too small to compete against thermal disorder or viscous effects in the case of lipid molecules. We tentatively propose that the interaction between the fatty acid chains’ electric moment and the external magnetic field is driving the lipid tails in the hydrophobic membrane core into a better ordered state.
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Affiliation(s)
- Jennifer Tang
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.
| | - Richard J Alsop
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.
| | - Karin Schmalzl
- JCNS, Forschungszentrum Jülich, Outstation at ILL, 38042 Grenoble, France.
| | - Richard M Epand
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, ON, L8S 4K1, Canada.
| | - Maikel C Rheinstädter
- Department of Physics and Astronomy, McMaster University, Hamilton, ON, L8S 4M1, Canada.
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Alsop RJ, Armstrong CL, Maqbool A, Toppozini L, Dies H, Rheinstädter MC. Cholesterol expels ibuprofen from the hydrophobic membrane core and stabilizes lamellar phases in lipid membranes containing ibuprofen. Soft Matter 2015; 11:4756-4767. [PMID: 25915907 DOI: 10.1039/c5sm00597c] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
There is increasing evidence that common drugs, such as aspirin and ibuprofen, interact with lipid membranes. Ibuprofen is one of the most common over the counter drugs in the world, and is used for relief of pain and fever. It interacts with the cyclooxygenase pathway leading to inhibition of prostaglandin synthesis. From X-ray diffraction of highly oriented model membranes containing between 0 and 20 mol% ibuprofen, 20 mol% cholesterol, and dimyristoylphosphatidylcholine (DMPC), we present evidence for a non-specific interaction between ibuprofen and cholesterol in lipid bilayers. At a low ibuprofen concentrations of 2 mol%, three different populations of ibuprofen molecules were found: two in the lipid head group region and one in the hydrophobic membrane core. At higher ibuprofen concentrations of 10 and 20 mol%, the lamellar bilayer structure is disrupted and a lamellar to cubic phase transition was observed. In the presence of 20 mol% cholesterol, ibuprofen (at 5 mol%) was found to be expelled from the membrane core and reside solely in the head group region of the bilayers. 20 mol% cholesterol was found to stabilize lamellar membrane structure and the formation of a cubic phase at 10 and 20 mol% ibuprofen was suppressed. The results demonstrate that ibuprofen interacts with lipid membranes and that the interaction is strongly dependent on the presence of cholesterol.
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Affiliation(s)
- Richard J Alsop
- Department of Physics and Astronomy, McMaster University, ABB-241, 1280 Main Street West, Hamilton, Ontario L8S 4M1, Canada.
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Alsop RJ, Toppozini L, Marquardt D, Kučerka N, Harroun TA, Rheinstädter MC. Aspirin inhibits formation of cholesterol rafts in fluid lipid membranes. Biochimica et Biophysica Acta (BBA) - Biomembranes 2015; 1848:805-12. [DOI: 10.1016/j.bbamem.2014.11.023] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 11/18/2014] [Accepted: 11/19/2014] [Indexed: 12/20/2022]
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