1
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McDougall DR, Deas R, Howard DL, Fitzgibbon QP, Smith GG, Jeffs AG, McGillivray DJ. Examining the inorganic elemental composition of lobster phyllosoma (Panulirus ornatus) with X-ray fluorescence microscopy. Metallomics 2023; 15:mfad038. [PMID: 37327074 PMCID: PMC10311473 DOI: 10.1093/mtomcs/mfad038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Accepted: 06/14/2023] [Indexed: 06/18/2023]
Abstract
The ornate spiny rock lobster, Panulirus ornatus, is an attractive candidate for aquaculture. The larval stages of spiny lobsters, known as phyllosoma, are complex with many developmental stages. Very little is known about the inorganic element composition of phyllosoma. In this study, a novel method using synchrotron X-ray fluorescence microscopy (XFM) was applied to investigate the distributions of metals potassium (K), calcium (Ca), copper (Cu), zinc (Zn), the metalloid arsenic (As), and nonmetal bromine (Br) within individual phyllosoma at stages 3, 4, and 8 of their development. For the first time, 1 µm resolution synchrotron XFM images of whole phyllosoma as well as closer examinations of their eyes, mouths, setae, and tails were obtained. Elements accumulated in certain locations within phyllosoma, providing insight into their likely biological role for these organisms. This information may be useful for the application of dietary supplementation in the future to closed larval cycle lobster aquaculture operations.
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Affiliation(s)
- Daniel R McDougall
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Robert Deas
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Daryl L Howard
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Quinn P Fitzgibbon
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bay 49, Hobart, Tasmania, Australia
| | - Gregory G Smith
- Institute for Marine and Antarctic Studies (IMAS), University of Tasmania, Private Bay 49, Hobart, Tasmania, Australia
| | - Andrew G Jeffs
- Institute of Marine Science, University of Auckland, Private Bay 92019, Auckland, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
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2
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Biswas S, Melton LD, Nelson ARJ, Le Brun AP, Heinrich F, McGillivray DJ, Xu AY. The Assembly Mechanism and Mesoscale Architecture of Protein-Polysaccharide Complexes Formed at the Solid-liquid Interface. Langmuir 2022; 38:12551-12561. [PMID: 36194692 DOI: 10.1021/acs.langmuir.2c02003] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Protein-polysaccharide composite materials have generated much interest due to their potential use in medical science and biotechnology. A comprehensive understanding of the assembly mechanism and the mesoscale architecture is needed for fabricating protein-polysaccharide composite materials with desired properties. In this study, complex assemblies were built on silica surfaces through a layer-by-layer (LbL) approach using bovine beta-lactoglobulin variant A (βLgA) and pectin as model protein and polysaccharide, respectively. We demonstrated the combined use of quartz crystal microbalance with dissipation monitoring (QCM-D) and neutron reflectometry (NR) for elucidating the assembly mechanism as well as the internal architecture of the protein-polysaccharide complexes formed at the solid-liquid interface. Our results show that βLgA and pectin interacted with each other and formed a cohesive matrix structure at the interface consisting of intertwined pectin chains that were cross-linked by βLgA-rich domains. Although the complexes were fabricated in an LbL fashion, the complexes appeared to be relatively homogeneous with βLgA and pectin molecules spatially distributed within the matrix structure. Our results also demonstrate that the density of βLgA-pectin complex assemblies increased with both the overall and local charge density of pectin molecules. Therefore, the physical properties of the protein-polysaccharide matrix structure, including density and level of hydration, can be tuned by using polysaccharides with varying charge patterns, thus promoting the development of composite materials with desired properties.
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Affiliation(s)
- Shanta Biswas
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana70803, United States
| | - Laurence D Melton
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland1142, New Zealand
| | - Andrew R J Nelson
- Australian Centre for Neutron Scattering, ANSTO, Locked Bag 2001, Kirrawee DC, New South Wales2232, Australia
| | - Anton P Le Brun
- Australian Centre for Neutron Scattering, ANSTO, Locked Bag 2001, Kirrawee DC, New South Wales2232, Australia
| | - Frank Heinrich
- Department of Physics, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania15213, United States
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Mail Stop 6102, Gaithersburg, Maryland20899, United States
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland1142, New Zealand
| | - Amy Y Xu
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana70803, United States
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3
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Ling H, McGillivray DJ, Jin J. Locking the Spiro Carbon in Spirobisindane Using Sulfur and Phosphorus to Form "Olympic Ring"-like Molecules. J Org Chem 2022; 87:4649-4653. [PMID: 35200013 DOI: 10.1021/acs.joc.1c03048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
To improve the rigidity of spirobisindane, it was intramolecularly locked by forming eight-membered rings via sulfur and phosphorus atoms to produce an interlocked polycyclic structure under mild conditions in good yields. By carefully analyzing the crystal structures, we noticed that the angle between the two benzene rings in the locked version is significantly smaller than that of the typical spirobisindane structure. Molecular modeling indicated that locking the spiro center can remarkably enhance the rigidity.
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Affiliation(s)
- Honglei Ling
- School of Chemical Sciences, The University of Auckland, Auckland 1142, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, Auckland 1142, New Zealand.,MacDiarmid Centre for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Jianyong Jin
- School of Chemical Sciences, The University of Auckland, Auckland 1142, New Zealand.,Dodd-Walls Centre for Quantum and Photonic Technologies, Dunedin 9056, New Zealand
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4
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Kihara S, Chan A, In E, Taleb N, Tollemache C, Yick S, McGillivray DJ. Detecting polystyrene nanoplastics using filter paper-based surface-enhanced Raman spectroscopy. RSC Adv 2022; 12:20519-20522. [PMID: 35919172 PMCID: PMC9286027 DOI: 10.1039/d2ra03395j] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [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: 05/31/2022] [Accepted: 06/16/2022] [Indexed: 11/21/2022] Open
Abstract
This work presents a novel filter paper-based method using surface-enhanced Raman spectroscopy (SERS), for detecting polystyrene nanoplastics (PSNPs).
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Affiliation(s)
- Shinji Kihara
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Andrew Chan
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Eugene In
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
| | - Nargiss Taleb
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
| | - Cherie Tollemache
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
| | - Samuel Yick
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Duncan J. McGillivray
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
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5
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Makinde ZO, van der Heijden NJ, Clyde D, Nam S, Brothers PJ, Malmström J, Granville S, Domigan LJ, McGillivray DJ, Williams DE. Geometric Frustration and Long-Range Ordering Induced by Surface Pressure Oscillation in a Langmuir-Blodgett Monolayer of Magnetic Soft Spheres. Langmuir 2021; 37:10150-10158. [PMID: 34384020 DOI: 10.1021/acs.langmuir.1c01577] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
As a step toward the bottom-up construction of magnonic systems, this paper demonstrates the use of a large-amplitude surface-pressure annealing technique to generate 2-D order in a Langmuir-Blodgett monolayer of magnetic soft spheres comprising a surfactant-encapsulated polyoxometalate. The films show a distorted square lattice interpreted as due to geometric frustration caused by 2-D confinement between soft walls, one being the air interface and the other the aqueous subphase. Hysteresis and relaxation phenomena in the 2-D layers are suggested to be due to folding and time-dependent interpenetration of surfactant chains.
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Affiliation(s)
- Zainab O Makinde
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Nadine J van der Heijden
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Daniel Clyde
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Seong Nam
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Penelope J Brothers
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
- Research School of Chemistry, The Australian National University, Canberra ACT 2601, Australia
| | - Jenny Malmström
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
- Department of Chemical and Materials Engineering, The University of Auckland, 20 Symonds St., Auckland 1010, New Zealand
| | - Simon Granville
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
- Robinson Research Institute, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Laura J Domigan
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
- Department of Chemical and Materials Engineering, The University of Auckland, 20 Symonds St., Auckland 1010, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
| | - David E Williams
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
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6
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Rani A, De Leon-Rodriguez LM, Kavianinia I, McGillivray DJ, Williams DE, Brimble MA. Synthesis and characterization of mono S-lipidated peptide hydrogels: a platform for the preparation of reactive oxygen species responsive materials. Org Biomol Chem 2021; 19:3665-3677. [PMID: 33908574 DOI: 10.1039/d1ob00355k] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [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
In this work we report the synthesis of mono lipidated peptides containing a 3-mercaptopropionate linker in the N-terminus by means of a photoinitiated thiol-ene reaction (S-lipidation). We evaluate the self-assembling and hydrogelation properties of a library of mono S-lipidated peptides containing lipid chains of various lengths and demonstrate that hydrogelation was driven by a balance between the lipid chain's hydrophobicity and the peptide's facial hydrophobicity. We further postulate that a simple calculation using estimated values of log D could be used as a predictor of hydrogelation when designing similar systems. A mono S-lipidated peptide containing a short lipid chain that formed hydrogels was fully characterized and a mechanism for the peptide hydrogelation developed. Finally, we demonstrate that the presence of the thioether group in the mono S-lipidated peptide hydrogels, which is a feature lacking in conventional N-acyl lipidated systems, enables the controlled disassembly of the gel via oxidation to the sulfoxide by reactive oxygen species in accordance with a hydrophobicity-modulated strategy. Thus, we conclude that mono S-lipidated peptide hydrogels constitute a novel and simple tool for the development of tissue engineering and targeted drug delivery applications of diseases with overexpression of reactive oxygen species (e.g. degenerative and metabolic diseases, and cancers).
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Affiliation(s)
- Aakanksha Rani
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - Luis M De Leon-Rodriguez
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand.
| | - Iman Kavianinia
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - David E Williams
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - Margaret A Brimble
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand
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7
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Kihara S, Köper I, Mata JP, McGillivray DJ. Reviewing nanoplastic toxicology: It's an interface problem. Adv Colloid Interface Sci 2021; 288:102337. [PMID: 33385776 DOI: 10.1016/j.cis.2020.102337] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/06/2020] [Accepted: 12/07/2020] [Indexed: 01/19/2023]
Abstract
Multiple international agencies have recently raised environmental and health concerns regarding plastics in nanoforms (nanoplastics), but there is insufficient knowledge of their properties to allow for an accurate risk assessment to be conducted and any risks managed. For this reason, research into the toxicity of nanoplastics has focused strongly on documenting their impacts on biological organisms. One scope of this review is to summarise the recent findings on the adverse effects on biological organisms and strategies which can be adopted to advance our understanding of nanoplastic properties and their toxicity. Specifically, a mechanistic approach has already been employed in nanotoxicology, which focuses on the cause-and-effect relationships to establish a tool that predicts the biological impacts based on nanoparticle characteristics. Identifying the chemical and biological bases behind the observed biological effects (such as in vitro cellular response) is a major challenge, due to the intricate nature of nanoparticle-biological molecule complexes and an unawareness of their interaction with other biological targets, particularly at interfacial level. An exemplary case includes protein corona formation and ecological molecule corona (eco-corona) for nanoplastics. Therefore, the second scope of this review is to discuss recent findings and importance of (for both non-plastic and plastic nanoparticles) coronae formation and structure. Finally, we discuss the opportunities provided by model system approaches (model protein corona and lipid bilayer) to deepen the understanding of the above-mentioned perspectives, and corroborate the findings from in vitro experiments.
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Affiliation(s)
- Shinji Kihara
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand; The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Ingo Köper
- Institute for Nanoscale Science and Technology, College for Science and Engineering, Flinders University, Adelaide, SA 5042, Australia
| | - Jitendra P Mata
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, New Illawarra Rd, Lucas Heights, NSW 2234, Australia.
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand; The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
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8
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McDougall DR, Kihara S, Reinhardt J, Miskelly GM, McGillivray DJ, Jeffs AG. Biodegradable chelating agent improves the survival of early larvae for shellfish aquaculture. Aquat Toxicol 2020; 228:105645. [PMID: 33010639 DOI: 10.1016/j.aquatox.2020.105645] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 08/28/2020] [Accepted: 09/20/2020] [Indexed: 06/11/2023]
Abstract
The toxicity of heavy metals commonly impacts the survival of crustacean and bivalve larvae in hatchery culture, and this has led to the widespread use of EDTA to decrease this toxicity. Since EDTA has a very poor biodegradability leading to potential persistent environmental effects, alternative methods to prevent heavy metal toxicity to shellfish larvae are needed. EDDS is a biodegradable potential alternative to EDTA for this application and was tested as a treatment of the seawater used for rearing aquaculture Greenshell™ mussel (Perna canaliculus) larval embryos in this study. Mussel embryos reared with EDTA or EDDS had significantly better survival than without. The concentrations and spatial distributions of heavy metals in D-veliger larvae as determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and X-ray Fluorescence Microscopy (XFM) suggested that chelating agents increased the levels of calcium in larvae while they reduced the concentration of zinc. In addition, where decreased accumulation of the other heavy metals was not observed, chelating agents affected their distribution within the larvae, especially for copper and arsenic. This is the first study to test the use of EDDS for aquaculture hatchery application and shows that EDDS is an effective biodegradable alternative to EDTA that can mitigate the effects of heavy metals for shellfish larval rearing.
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Affiliation(s)
- Daniel R McDougall
- Institute of Marine Science, University of Auckland, Private Bag 92019, Auckland, New Zealand.
| | - Shinji Kihara
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Juliane Reinhardt
- Australian Synchrotron, Australian Nuclear Science and Technology Organisation, Clayton, Victoria 3168, Australia
| | - Gordon M Miskelly
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Andrew G Jeffs
- Institute of Marine Science, University of Auckland, Private Bag 92019, Auckland, New Zealand
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9
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Sabet S, Seal CK, Akbarinejad A, Rashidinejad A, McGillivray DJ. “Positive-negative-negative”: a colloidal delivery system for bioactive compounds. Food Hydrocoll 2020. [DOI: 10.1016/j.foodhyd.2020.105922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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10
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Makinde ZO, van der Heijden NJ, Domigan LJ, McGillivray DJ, Williams DE. Aligned Assembly in a 2-D Gel of a Water-Soluble Peptide. Langmuir 2020; 36:11292-11302. [PMID: 32882136 DOI: 10.1021/acs.langmuir.0c01944] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
We demonstrate the assembly of a compact, gel-like Langmuir-Blodgett film of rods formed by self-assembly of a β-sheet-forming water-soluble peptide, Ac-IKHLSVN-NH2, at the surface of aqueous electrolytes. We characterize surface pressure hysteresis and demonstrate shear stiffening of the surface caused by area cycling, which we interpret as due to rearrangement and alignment of the rods. We show strong effects of the electrolyte on the assembly of the elementary rods, which can be related to the Hofmeister series and interpreted by effects on the interaction energies mediated by ions and water. Formation of β-sheet structures and assembly of these into surface-segregated semicrystalline gels was strongly promoted by ammonium sulfate electrolyte. With ammonium sulfate electrolyte as subphase for Langmuir-Blodgett film deposition, shear stiffening by surface area cycling resulted in very compact films on transfer to a substrate.
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Affiliation(s)
- Zainab O Makinde
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Nadine J van der Heijden
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Laura J Domigan
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
- Department of Chemical and Materials Engineering, The University of Auckland, Auckland 1010, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
| | - David E Williams
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, Victoria University of Wellington, Wellington 6140, New Zealand
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11
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Rani A, Kavianinia I, De Leon-Rodriguez LM, McGillivray DJ, Williams DE, Brimble MA. Nanoribbon self-assembly and hydrogel formation from an NOctanoyl octapeptide derived from the antiparallel β-Interface of a protein homotetramer. Acta Biomater 2020; 114:233-243. [PMID: 32682054 DOI: 10.1016/j.actbio.2020.07.023] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 07/09/2020] [Accepted: 07/09/2020] [Indexed: 12/26/2022]
Abstract
The effect of installing different lipid chains (C6, C8, C10, and C16) on the N-terminus of an octapeptide derived from the antiparallel β-interface of the diaminopimelate decarboxylase protein homotetramer has been investigated. Notably, the C8 peptide conjugate assembled into wide twisted nanoribbons and formed hydrogels, which to the best of our knowledge constitutes the first example of a peptide containing an eight carbon alkyl chain that demonstrates these properties, a space typically occupied by peptide amphiphiles with long lipid chains. Furthermore, this self-assembling lipopeptide exhibited pH and temperature stability with shear thinning properties suitable for biomedical applications. Importantly, in this work the application of the polystyrene-based sorbent Diaion™ HP20SS for the simple large-scale purification of self-assembling peptides is presented as an alternative to the use of time-consuming and labor-intensive reverse-phase high-performance liquid chromatography. STATEMENT OF SIGNIFICANCE: Peptides that can self-assemble into defined nanostructures are highly attractive for many biomedical applications given their unique physical and chemical properties. It is recognized that self-assembling peptides derived from naturally occurring proteins offer an unlimited source of functionalities and structures, which are hard to uncover with designed sequences. In this study, we have investigated the effect of installing different lipids chains on the N-terminus of an octapeptide derived from the antiparallel β-interface of the diaminopimelate decarboxylase protein homo tetramer. We also reported the use of polymeric DiaionⓇ HP20SS beads as an alternative solid support to purify self-assembling peptides.
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Affiliation(s)
- Aakanksha Rani
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand; School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - Iman Kavianinia
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand; School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand
| | - Luis M De Leon-Rodriguez
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand; School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - David E Williams
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand; School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - Margaret A Brimble
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand; School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand; MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand; Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand.
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12
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Rani A, Kavianinia I, Hume P, De Leon-Rodriguez LM, Kihara S, Williams DE, McGillivray DJ, Plank NOV, Gerrard J, Hodgkiss JM, Brimble MA. Directed self-assembly of peptide-diketopyrrolopyrrole conjugates - a platform for bio-organic thin film preparation. Soft Matter 2020; 16:6563-6571. [PMID: 32588868 DOI: 10.1039/d0sm01071e] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [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
Increased water solubility and long-range intermolecular ordering have been introduced into the fluorescent organic molecule thiophene-diketopyrrolopyrrole (TDPP) via its conjugation to the octapeptide HEFISTAH, which is derived from the protein-protein β-interface of the homo-tetramer protein diaminopimelate decarboxylase. The octapeptide, and its TDPP mono- and cross-linked conjugates were synthesised using 9-fluorenylmethoxycarbonyl (Fmoc) based solid-phase peptide synthesis (SPPS). Unlike the unmodified peptide, the resulting mono-linked and cross-linked peptides showed a fibrous morphology and formed hydrogels at 4 wt% in water at neutral pH, but failed to assemble at pH 2 and pH 9. Further peptide characterization showed that the TDPP organic core enhances peptide self-assembly and that both peptides assembled into fibers with a parallel β-sheet structure. Furthermore, UV-vis spectroscopic analysis suggests that the TDPP molecules form H-type aggregates where the chromophores are likely to be co-facially packed, but rotationally and/or laterally offset from one another. This intermolecular coupling indicates that π-π stacking interactions are highly likely - a favourable sign for charge transport. The enhanced aqueous solubility and self-assembling properties of the TDPP-peptide conjugates allowed the successful preparation of thin films. Atomic force microscopy, X-ray diffraction and UV-vis spectroscopic analysis of these thin films revealed that the hybrid materials retained a fibrous morphology, β-sheet structures and strong intermolecular coupling between neighbouring TDPP molecules. These results open an exciting avenue for bio-organic materials development, through structural and electronic tuning of the TDPP core.
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Affiliation(s)
- Aakanksha Rani
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - Iman Kavianinia
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand
| | - Paul Hume
- MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand and School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6021, New Zealand
| | - Luis M De Leon-Rodriguez
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand.
| | - Shinji Kihara
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - David E Williams
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - Natalie O V Plank
- MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand and School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6021, New Zealand
| | - Juliet Gerrard
- School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand
| | - Justin M Hodgkiss
- MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand and School of Chemical and Physical Sciences, Victoria University of Wellington, Wellington 6021, New Zealand
| | - Margaret A Brimble
- School of Chemical Sciences, The University of Auckland, 23 Symonds St., Auckland 1010, New Zealand. and School of Biological Sciences, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand and MacDiarmid Institute for Advanced Materials and Nanotechnology, New Zealand and Maurice Wilkins Centre for Molecular Biodiscovery, The University of Auckland, 3A Symonds St., Auckland 1010, New Zealand
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13
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McDougall DR, Chan A, McGillivray DJ, de Jonge MD, Miskelly GM, Jeffs AG. Examining the role of ethylenediaminetetraacetic acid (EDTA) in larval shellfish production in seawater contaminated with heavy metals. Aquat Toxicol 2019; 217:105330. [PMID: 31704581 DOI: 10.1016/j.aquatox.2019.105330] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2019] [Revised: 10/04/2019] [Accepted: 10/07/2019] [Indexed: 06/10/2023]
Abstract
Heavy metal pollution is a concern in many coastal locations where it is frequently deleterious to the survival of young shellfish. Consequently, a great number of commercial shellfish hatcheries around the world rely on the addition of ethylenediaminetetraacetic acid (EDTA) to seawater to ensure successful larval production. Despite the importance of this practice to global shellfish production the mode of action of EDTA in larval production remains undetermined. It is assumed EDTA chelates heavy metals in seawater preventing interference in larval development. Larval mussels (Perna canaliculus) raised in seawater with 3 μM EDTA had a 15 fold higher yield than those without EDTA. The concentration and spatial arrangement of heavy metals in larvae as determined by Inductively Coupled Plasma Mass Spectrometry (ICPMS) and X-ray Fluorescence Microscopy (XFM) was consistent with reduced bioavailability of several metals, especially copper and zinc. This is the first study to confirm the effectiveness of EDTA for managing metal pollution commonly encountered in coastal shellfish hatcheries.
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Affiliation(s)
- Daniel R McDougall
- Institute of Marine Science, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
| | - Andrew Chan
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Martin D de Jonge
- Australian Synchrotron, Australian Nuclear Science and Technology Organisation, Clayton, Victoria 3168, Australia
| | - Gordon M Miskelly
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Andrew G Jeffs
- Institute of Marine Science, The University of Auckland, Private Bag 92019, Auckland, New Zealand
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14
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Chen D, Melton LD, McGillivray DJ, Ryan TM, Harris PJ. Changes in the orientations of cellulose microfibrils during the development of collenchyma cell walls of celery (Apium graveolens L.). Planta 2019; 250:1819-1832. [PMID: 31463558 DOI: 10.1007/s00425-019-03262-8] [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] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Accepted: 08/14/2019] [Indexed: 06/10/2023]
Abstract
During development, cellulose microfibrils in collenchyma walls become increasingly longitudinal, as determined by small-angle X-ray scattering, despite the walls maintaining a fine structure indicative of a crossed-polylamellate structure. Collenchyma cells have thickened primary cell walls and provide mechanical support during plant growth. During their development, these cells elongate and their walls thicken considerably. We used microscopy and synchrotron small-angle X-ray scattering to study changes in the orientations of cellulose microfibrils that occur during development in the walls of collenchyma cells present in peripheral strands in celery (Apium graveolens) petioles. Transmission electron microscopy showed that the walls consisted of many lamellae (polylamellate), with lamellae containing longitudinally oriented cellulose microfibrils alternating with microfibrils oriented at higher angles. The lamellae containing longitudinally oriented microfibrils predominated at later stages of development. Nevertheless, transmission electron microscopy of specially stained, oblique sections provided evidence that the cellulose microfibrils were ordered throughout development as crossed-polylamellate structures. These results are consistent with our synchrotron small-angle X-ray scattering results that showed the cellulose microfibrils become oriented increasingly longitudinally during development. Some passive reorientation of cellulose microfibrils may occur during development, but extensive reorientation throughout the wall would destroy ordered structures. Atomic force microscopy and field emission scanning electron microscopy were used to determine the orientations of newly deposited cellulose microfibrils. These were found to vary widely among different cells, which could be consistent with the formation of crossed-polylamellate structures. These newly deposited cellulose microfibrils are deposited in a layer of pectic polysaccharides that lies immediately outside the plasma membrane. Overall, our results show that during development of collenchyma walls, the cellulose microfibrils become increasingly longitudinal in orientation, yet organized, crossed-polylamellate structures are maintained.
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Affiliation(s)
- Da Chen
- School of Chemical Sciences, The University of Auckland, Auckland Mail Centre, Private Bag 92019, Auckland, 1142, New Zealand
- Department of Food Science, Purdue University, 745 Agriculture Mall Drive, West Lafayette, IN, 47907, USA
| | - Laurence D Melton
- School of Chemical Sciences, The University of Auckland, Auckland Mail Centre, Private Bag 92019, Auckland, 1142, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, Auckland Mail Centre, Private Bag 92019, Auckland, 1142, New Zealand
- The MacDiarmid Institute, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Timothy M Ryan
- The MacDiarmid Institute, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
- The Australian Synchrotron, 800 Blackburn Rd, Clayton, VIC, 3168, Australia
| | - Philip J Harris
- School of Biological Sciences, The University of Auckland, Auckland Mail Centre, Private Bag 92019, Auckland, 1142, New Zealand.
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15
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Kihara S, De Zoysa GH, Shahlori R, Vadakkedath PG, Ryan TM, Mata JP, Sarojini V, McGillivray DJ. Solution structure of linear battacin lipopeptides - the effect of lengthening fatty acid chain. Soft Matter 2019; 15:7501-7508. [PMID: 31528955 DOI: 10.1039/c9sm00932a] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
In recent years, lipopeptides have received attention for their enhanced antimicrobial activity, especially against multi-drug resistant (MDR) pathogens. We have previously reported that the bacterial soil extracted, novel cyclic lipopeptide, battacin, and its synthetic analogues have enhanced antimicrobial activity against various Gram negative, Gram positive and fungal pathogens. In particular, the modification of the hydrophobic fatty acid chain and molecular structure has improved its activity. We have used small angle X-ray scattering (SAXS) and circular dichroism (CD) to characterise the low resolution structure of battacin lipopeptides containing covalently bonded fatty acid chains and the one without it. In the absence of fatty acids or with short fatty acid chain, the peptides adopted an extended random coil structure that is best described barbell-like shape, while fatty acids that are sufficiently long induced an aggregation into a ∼4.0 nm diameter core shell sphere. While the kinked structure found within this barbell shape may have a role in antimicrobial activities, the self-assembly of the battacin analogue with the longest fatty acid chain may have a correlation to the declined antibacterial activities.
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Affiliation(s)
- Shinji Kihara
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand.
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16
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Kihara S, van der Heijden NJ, Seal CK, Mata JP, Whitten AE, Köper I, McGillivray DJ. Soft and Hard Interactions between Polystyrene Nanoplastics and Human Serum Albumin Protein Corona. Bioconjug Chem 2019; 30:1067-1076. [DOI: 10.1021/acs.bioconjchem.9b00015] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shinji Kihara
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Nadine J. van der Heijden
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Chris K. Seal
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Jitendra P. Mata
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234, Australia
| | - Andrew E. Whitten
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Lucas Heights, New South Wales 2234, Australia
| | - Ingo Köper
- Institute for Nanoscale Science and Technology, College for Science and Engineering, Flinders University, Adelaide, South Australia 5042, Australia
| | - Duncan J. McGillivray
- School of Chemical Sciences, The University of Auckland, Auckland 1010, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
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17
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Mansel BW, Irani AH, Ryan TM, McGillivray DJ, Chen HL, Williams MAK. Resolving solution conformations of the model semi-flexible polyelectrolyte homogalacturonan using molecular dynamics simulations and small-angle x-ray scattering. Eur Phys J E Soft Matter 2019; 42:19. [PMID: 30788674 DOI: 10.1140/epje/i2019-11776-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2018] [Accepted: 01/04/2019] [Indexed: 05/27/2023]
Abstract
The conformation of polyelectrolytes in the solution state has long been of interest in polymer science. Herein we utilize all atom molecular dynamics simulations (MD) and small-angle x-ray scattering experiments (SAXS) to elucidate the molecular structure of the model polyelectrolyte homogalacturonan. Several degrees of polymerization were studied and in addition partial methylesterification of the otherwise charge-carrying carboxyl groups was used in order to generate samples with varying intra-chain charge distributions. It is shown that at length scales above around 1nm the conformation of isolated chains has surprisingly little dependence on the charge distribution or the concentration of attendant monovalent salts, reflective of the intrinsic stiffness of the saccharide rings and the dynamical constraints of the glycosidic linkage. Indeed the conformation of isolated chains over all accessible length scales is well described by the atomic coordinates available from fibre diffraction studies. Furthermore, in more concentrated systems it is shown that, after careful analysis of the SAXS data, the form of the inter-particle effects heralded by the emergence of a so-called polyelectrolyte peak, can be extracted, and that this phenomena can be reproduced by multiple chain MD simulations.
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Affiliation(s)
- Bradley W Mansel
- Department of Chemical Engineering, National Tsing Hua University, 30013, Hsinchu, Taiwan.
| | - Amir Hossein Irani
- Institute of Fundamental Sciences, Massey University, 4474, Palmerston North, New Zealand
| | | | - Duncan J McGillivray
- School of Chemical Sciences, University of Auckland, Private Bag 90219, Auckland, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, 6140, Wellington, New Zealand
| | - Hsin-Lung Chen
- Department of Chemical Engineering, National Tsing Hua University, 30013, Hsinchu, Taiwan
| | - Martin A K Williams
- Institute of Fundamental Sciences, Massey University, 4474, Palmerston North, New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, 6140, Wellington, New Zealand
- Riddet Institute, Massey University, 4474, Palmerston North, New Zealand
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18
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Baek P, Mata JP, Sokolova A, Nelson A, Aydemir N, Shahlori R, McGillivray DJ, Barker D, Travas-Sejdic J. Chain shape and thin film behaviour of poly(thiophene)-graft-poly(acrylate urethane). Soft Matter 2018; 14:6875-6882. [PMID: 30083686 DOI: 10.1039/c8sm00777b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Electronic graft copolymers with conjugated polymer backbones are emerging as promising materials for various organic electronics. These materials combine the advantages of organic electronic materials, such as molecular tunability of opto-electronic and electrochemical properties, with solution processability and other 'designer' physical and mechanical properties imparted through the addition of grafted polymer side chains. Future development of such materials with complex molecular architecture requires a better understanding of the effect of molecular parameters, such as side chain length, on the structure and, in turn, on the electronic properties. In this study, poly(thiophene)-graft-poly(acrylate urethane) (PTh-g-PAU) was examined as a model system and we investigate the effect of side chain length on the overall shape and size in solution. Furthermore, the changes in the swelling behaviour of the graft copolymer thin films help in understanding their electrochemical redox properties.
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Affiliation(s)
- Paul Baek
- Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand. and The MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Jitendra P Mata
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, NSW 2234, Australia
| | - Anna Sokolova
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, NSW 2234, Australia
| | - Andrew Nelson
- Australian Centre for Neutron Scattering, Australian Nuclear Science and Technology Organization, NSW 2234, Australia
| | - Nihan Aydemir
- Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand. and The MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Rayomand Shahlori
- Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand. and The MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - Duncan J McGillivray
- Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand. and The MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
| | - David Barker
- Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Jadranka Travas-Sejdic
- Polymer Electronics Research Centre, School of Chemical Sciences, University of Auckland, Auckland 1010, New Zealand. and The MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
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19
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Shahlori R, McDougall DR, Waterhouse GIN, Yao F, Mata JP, Nelson ARJ, McGillivray DJ. Biomineralization of Calcium Phosphate and Calcium Carbonate within Iridescent Chitosan/Iota-Carrageenan Multilayered Films. Langmuir 2018; 34:8994-9003. [PMID: 29961323 DOI: 10.1021/acs.langmuir.8b00434] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This work systematically explores the biomineralization of calcium phosphate (CaP) and carbonate (CaCO3) within chitosan/iota-carrageenan multilayer films. Multilayer films of chitosan and iota-carrageenan (up to 128-coupled layers) were prepared on glass substrates by a layer-by-layer dip-coating technique. Cryo-scanning electron microscopy revealed dense interfaces between the chitosan and iota-carrageenan layers with thicknesses in the range 250 and 350 nm in the hydrated state, accounting for the iridescent nature of multilayer films when wet. Immersion of the multilayered films in simulated body fluid or simulated seawater at 25 °C resulted in the mineralization of CaP and CaCO3, respectively, at the interfaces between the biopolymer layers and modified the iridescence of the films. Lamellar scattering features in small-angle neutron scattering measurements of the mineralized films provided evidence of the localized mineralization. Further evidence of this was found through the lack of change in the dynamic and static correlation lengths of the polymer networks within the bulk phase of the chitosan and iota-carrageenan layers. CaP mineralization occurred to a greater extent than CaCO3 mineralization within the films, evidenced by the higher lamellar density and greater rigidity of the CaP-mineralized films. Results provide valuable new insights into CaP and CaCO3 biomineralization in biopolymer networks.
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Affiliation(s)
- Rayomand Shahlori
- School of Chemical Sciences , University of Auckland , Private Bag, 90219 Auckland , New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology , Wellington 6140 , New Zealand
| | - Daniel R McDougall
- School of Chemical Sciences , University of Auckland , Private Bag, 90219 Auckland , New Zealand
| | - Geoffrey I N Waterhouse
- School of Chemical Sciences , University of Auckland , Private Bag, 90219 Auckland , New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology , Wellington 6140 , New Zealand
| | - Feihong Yao
- School of Chemical Sciences , University of Auckland , Private Bag, 90219 Auckland , New Zealand
| | - Jitendra P Mata
- Australian Nuclear Science and Technology Organization , Locked Bag 2001, Kirrawee DC , New South Wales 2232 , Australia
| | - Andrew R J Nelson
- Australian Nuclear Science and Technology Organization , Locked Bag 2001, Kirrawee DC , New South Wales 2232 , Australia
| | - Duncan J McGillivray
- School of Chemical Sciences , University of Auckland , Private Bag, 90219 Auckland , New Zealand
- The MacDiarmid Institute for Advanced Materials and Nanotechnology , Wellington 6140 , New Zealand
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20
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Xu AY, Melton LD, Ryan TM, Mata JP, Rekas A, Williams MA, McGillivray DJ. Effects of polysaccharide charge pattern on the microstructures of β-lactoglobulin-pectin complex coacervates, studied by SAXS and SANS. Food Hydrocoll 2018. [DOI: 10.1016/j.foodhyd.2017.11.045] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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21
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Hae Cho CA, Liang C, Perera J, Liu J, Varnava KG, Sarojini V, Cooney RP, McGillivray DJ, Brimble MA, Swift S, Jin J. Molecular Weight and Charge Density Effects of Guanidinylated Biodegradable Polycarbonates on Antimicrobial Activity and Selectivity. Biomacromolecules 2017; 19:1389-1401. [DOI: 10.1021/acs.biomac.7b01245] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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22
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Mbenza NM, Vadakkedath PG, McGillivray DJ, Leung IKH. NMR studies of the non-haem Fe(II) and 2-oxoglutarate-dependent oxygenases. J Inorg Biochem 2017; 177:384-394. [PMID: 28893416 DOI: 10.1016/j.jinorgbio.2017.08.032] [Citation(s) in RCA: 4] [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: 04/24/2017] [Revised: 08/21/2017] [Accepted: 08/30/2017] [Indexed: 01/13/2023]
Abstract
The non-haem Fe(II) and 2-oxoglutarate (2OG)-dependent oxygenases belong to a superfamily of structurally-related enzymes that play important biological roles in plants, microorganisms and animals. Structural, mechanistic and functional studies of 2OG oxygenases require efficient and effective biophysical tools. Nuclear magnetic resonance (NMR) spectroscopy is a useful tool to study this enzyme superfamily. It has been applied to obtain information about enzyme kinetics, identify and characterise 2OG oxygenase-catalysed oxidation products, elucidate the catalytic mechanism, monitor ligand binding and study protein dynamics. This review summarises the types of information that NMR spectroscopy can provide in the studies of 2OG oxygenases, highlights the advantages of the technique and describes its drawbacks.
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Affiliation(s)
- Naasson M Mbenza
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Victoria Street West, Auckland 1142, New Zealand
| | - Praveen G Vadakkedath
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Victoria Street West, Auckland 1142, New Zealand.; MacDiarmid Institute for Advanced Materials and Nanotechnology, PO Box 600, Wellington 6140, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Victoria Street West, Auckland 1142, New Zealand.; MacDiarmid Institute for Advanced Materials and Nanotechnology, PO Box 600, Wellington 6140, New Zealand
| | - Ivanhoe K H Leung
- School of Chemical Sciences, The University of Auckland, Private Bag 92019, Victoria Street West, Auckland 1142, New Zealand..
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23
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Akers PW, Dingley AJ, Swift S, Nelson ARJ, Martin J, McGillivray DJ. Using Neutron Reflectometry to Characterize Antimicrobial Protein Surface Coatings. J Phys Chem B 2017; 121:5908-5916. [DOI: 10.1021/acs.jpcb.7b02886] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Peter W. Akers
- School
of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Andrew J. Dingley
- Institute of Complex
Systems: Strukturbiochemie (ICS-6), Forschungszentrum Jülich, 52425 Jülich, Germany
- Institut
für Physikalische Biologie, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany
| | - Simon Swift
- Department
of Molecular Medicine and Pathology, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Andrew R. J. Nelson
- Australian
Centre for Neutron Scattering, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, New South
Wales 2232, Australia
| | - Julie Martin
- School
of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Duncan J. McGillivray
- School
of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
- MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington 6140, New Zealand
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24
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Xu AY, Melton LD, Ryan TM, Mata JP, Jameson GB, Rekas A, Williams MAK, McGillivray DJ. Sugar-coated proteins: the importance of degree of polymerisation of oligo-galacturonic acid on protein binding and aggregation. Soft Matter 2017; 13:2698-2707. [PMID: 28337496 DOI: 10.1039/c6sm02660e] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
We have simplified the structural heterogeneity of protein-polysaccharide binding by investigating protein binding to oligosaccharides. The interactions between bovine beta-lactoglobulin A (βLgA) and oligo-galacturonic acids (OGAs) with various numbers of sugar residues have been investigated with a range of biophysical techniques. We show that the βLgA-OGA interaction is critically dependent on the length of the oligosaccharide. Isothermal titration calorimetry results suggest that a minimum length of 7 or 8 sugar residues is required in order to exhibit appreciable exothermic interactions with βLgA - shorter oligosaccharides show no enthalpic interactions at any concentration ratio. When titrating βLgA into OGAs with more than 7-8 sugar residues the sample solution also became turbid with increasing amounts of βLgA, indicating the formation of macroscopic assemblies. Circular dichroism, thioflavin T fluorescence and small angle X-ray/neutron scattering experiments revealed two structural regimes during the titration. When OGAs were in excess, βLgA formed discrete assemblies upon OGA binding, and no subsequent aggregation was observed. However, when βLgA was present in excess, multi-scale structures were formed and this eventually led to the separation of the solution into two liquid-phases.
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Affiliation(s)
- Amy Y Xu
- Riddet Institute Centre of Research Excellence, Private Bag 11222, Palmerston North 4442, New Zealand and School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | - Laurence D Melton
- Riddet Institute Centre of Research Excellence, Private Bag 11222, Palmerston North 4442, New Zealand and School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand.
| | - Timothy M Ryan
- Australian Synchrotron, Clayton 3168, Victoria, Australia and The MacDiarmid Institute, Private Bag 600, Wellington 6140, New Zealand
| | - Jitendra P Mata
- ACNS, Australian Nuclear Science and Technology Organisation (ANSTO), Private Bag 2001, NSW 2232, Australia
| | - Geoffrey B Jameson
- Riddet Institute Centre of Research Excellence, Private Bag 11222, Palmerston North 4442, New Zealand and Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
| | - Agata Rekas
- National Deuteration Facility, Australian Nuclear Science and Technology Organisation (ANSTO), Private Bag 2001, NSW 2232, Australia
| | - Martin A K Williams
- Riddet Institute Centre of Research Excellence, Private Bag 11222, Palmerston North 4442, New Zealand and The MacDiarmid Institute, Private Bag 600, Wellington 6140, New Zealand and Institute of Fundamental Sciences, Massey University, Private Bag 11222, Palmerston North 4442, New Zealand
| | - Duncan J McGillivray
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. and The MacDiarmid Institute, Private Bag 600, Wellington 6140, New Zealand
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Kirby N, Cowieson N, Hawley AM, Mudie ST, McGillivray DJ, Kusel M, Samardzic-Boban V, Ryan TM. Improved radiation dose efficiency in solution SAXS using a sheath flow sample environment. Acta Crystallogr D Struct Biol 2016; 72:1254-1266. [PMID: 27917826 PMCID: PMC5137223 DOI: 10.1107/s2059798316017174] [Citation(s) in RCA: 117] [Impact Index Per Article: 14.6] [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: 09/21/2016] [Accepted: 10/25/2016] [Indexed: 12/24/2022]
Abstract
Coflow is a new method for delivering radiation-sensitive biological and other solution-based samples to high-brightness X-ray beamlines that exploits laminar flow to ameliorate radiation-damage limitations and provides a host of practical improvements associated with these types of experiments. Radiation damage is a major limitation to synchrotron small-angle X-ray scattering analysis of biomacromolecules. Flowing the sample during exposure helps to reduce the problem, but its effectiveness in the laminar-flow regime is limited by slow flow velocity at the walls of sample cells. To overcome this limitation, the coflow method was developed, where the sample flows through the centre of its cell surrounded by a flow of matched buffer. The method permits an order-of-magnitude increase of X-ray incident flux before sample damage, improves measurement statistics and maintains low sample concentration limits. The method also efficiently handles sample volumes of a few microlitres, can increase sample throughput, is intrinsically resistant to capillary fouling by sample and is suited to static samples and size-exclusion chromatography applications. The method unlocks further potential of third-generation synchrotron beamlines to facilitate new and challenging applications in solution scattering.
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Affiliation(s)
- Nigel Kirby
- SAXS/WAXS, Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Nathan Cowieson
- B21 SAXS, Diamond Light Source Ltd, Hartwell Science and Innovation Campus, Didcot OX11 0DE, England
| | - Adrian M Hawley
- SAXS/WAXS, Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Stephen T Mudie
- SAXS/WAXS, Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Duncan J McGillivray
- School of Chemical Sciences, University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Michael Kusel
- Kusel Design, 6 Hambleton Street, Albert Park, Victoria 3206, Australia
| | - Vesna Samardzic-Boban
- SAXS/WAXS, Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Timothy M Ryan
- SAXS/WAXS, Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
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Hettiarachchi CA, Melton LD, Williams MAK, McGillivray DJ, Gerrard JA, Loveday SM. Morphology of complexes formed between β
-lactoglobulin nanofibrils and pectins is influenced by the pH and structural characteristics of the pectins. Biopolymers 2016; 105:819-31. [DOI: 10.1002/bip.22917] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 07/02/2016] [Accepted: 07/05/2016] [Indexed: 01/06/2023]
Affiliation(s)
- Charith A. Hettiarachchi
- Riddet Institute, Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
- School of Chemical Sciences; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand
- Department of Food Science and Technology, Faculty of Agriculture; University of Peradeniya; Peradeniya 20400 Sri Lanka
| | - Laurence D. Melton
- Riddet Institute, Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
- School of Chemical Sciences; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand
| | - Martin A. K. Williams
- Riddet Institute, Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology; Wellington 6140 New Zealand
- Institute of Fundamental Sciences, Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
| | - Duncan J. McGillivray
- Riddet Institute, Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
- School of Chemical Sciences; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology; Wellington 6140 New Zealand
| | - Juliet A. Gerrard
- Riddet Institute, Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
- School of Chemical Sciences; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology; Wellington 6140 New Zealand
- School of Biological Sciences; University of Auckland; Private Bag 92019 Auckland 1142 New Zealand
| | - Simon M. Loveday
- Riddet Institute, Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
- Massey Institute of Food Science and Technology, Massey University; Private Bag 11222 Palmerston North 4442 New Zealand
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27
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Hettiarachchi CA, Melton LD, McGillivray DJ, Loveday SM, Gerrard JA, Williams MAK. β-Lactoglobulin nanofibrils can be assembled into nanotapes via site-specific interactions with pectin. Soft Matter 2016; 12:756-768. [PMID: 26517088 DOI: 10.1039/c5sm01530h] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Controlling the self-assembly of individual supramolecular entities, such as amyloid fibrils, into hierarchical architectures enables the 'bottom-up' fabrication of useful bionanomaterials. Here, we present the hierarchical assembly of β-lactoglobulin nanofibrils into the form of 'nanotapes' in the presence of a specific pectin with a high degree of methylesterification. The nanotapes produced were highly ordered, and had an average width of 180 nm at pH 3. Increasing the ionic strength or the pH of the medium led to the disassembly of nanotapes, indicating that electrostatic interactions stabilised the nanotape architecture. Small-angle X-ray scattering experiments conducted on the nanotapes showed that adequate space is available between adjacent nanofibrils to accommodate pectin molecules. To locate the interaction sites on the pectin molecule, it was subjected to endopolygalacturonase digestion, and the resulting products were analysed using capillary electrophoresis and size-exclusion chromatography for their charge and molecular weight, respectively. Results suggested that the functional pectin molecules carry short (<10 residues) enzyme-susceptible blocks of negatively charged, non-methylesterified galacturonic acid residues in the middle of their homogalacturonan backbones (and possibly near their ends), that specifically bind to sites on the nanofibrils. Blocking the interaction sites on the nanofibril surface using small oligomers of non-methylesterified galacturonic acid residues similar in size to the interaction sites of the pectin molecule decreased the nanotape formation, indicating that site-specific electrostatic interactions are vital for the cross-linking of nanofibrils. We propose a structural model for the pectin-cross-linked β-lactoglobulin nanotapes, the elements of which will inform the future design of bionanomaterials.
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28
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Ryan TM, Griffin MDW, McGillivray DJ, Knott RB, Wood K, Masters CL, Kirby N, Curtain CC. Apolipoprotein C-II Adopts Distinct Structures in Complex with Micellar and Submicellar Forms of the Amyloid-Inhibiting Lipid-Mimetic Dodecylphosphocholine. Biophys J 2016; 110:85-94. [PMID: 26745412 PMCID: PMC4805880 DOI: 10.1016/j.bpj.2015.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [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: 08/18/2015] [Revised: 11/03/2015] [Accepted: 11/09/2015] [Indexed: 01/21/2023] Open
Abstract
The formation of amyloid deposits is a common feature of a broad range of diseases, including atherosclerosis, Alzheimer's disease, and Parkinson's disease. The basis and role of amyloid deposition in the pathogenesis of these diseases is still being defined, however an interesting feature of amyloidogenic proteins is that the majority of the pathologically associated proteins are involved in lipid homeostasis, be it in lipid transport, incorporation into membranes, or the regulation of lipid pathways. Thus, amyloid-forming proteins commonly bind lipids, and lipids are generally involved in the proper folding of these proteins. However, understanding of the basis for these lipid-related aspects of amyloidogenesis is lacking. Thus, we have used the apolipoprotein C-II amyloid model system in conjunction with x-ray and neutron scattering analyses to address this problem. Apolipoprotein C-II is a well-studied model system of systemic amyloid fibril formation, with a clear and well-defined pathway for fibril formation, where the effects of lipid interaction are characterized, particularly for the lipid mimetic dodecylphosphocholine. We show that the micellar state of an inhibitory lipid can have a very significant effect on protein conformation, with micelles stabilizing a particular α-helical structure, whereas submicellar lipids stabilize a very different dimeric, α-helical structure. These results indicate that lipids may have an important role in the development and progression of amyloid-related diseases.
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Affiliation(s)
- Timothy M Ryan
- Australian Synchrotron, Clayton, Victoria, Australia; The Florey Institute, The University of Melbourne, Parkville, Victoria, Australia; The MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington, New Zealand.
| | - Michael D W Griffin
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Duncan J McGillivray
- School of Chemical Science, The University of Auckland, Auckland, New Zealand; The MacDiarmid Institute of Advanced Materials and Nanotechnology, Wellington, New Zealand
| | - Robert B Knott
- Australian Nuclear Science and Technology Organisation, New South Wales, Australia
| | - Kathleen Wood
- Australian Nuclear Science and Technology Organisation, New South Wales, Australia
| | - Colin L Masters
- The Florey Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Nigel Kirby
- Australian Synchrotron, Clayton, Victoria, Australia
| | - Cyril C Curtain
- The Florey Institute, The University of Melbourne, Parkville, Victoria, Australia
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29
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Yang Z, Hemar Y, Hilliou L, Gilbert EP, McGillivray DJ, Williams MAK, Chaieb S. Nonlinear Behavior of Gelatin Networks Reveals a Hierarchical Structure. Biomacromolecules 2015; 17:590-600. [DOI: 10.1021/acs.biomac.5b01538] [Citation(s) in RCA: 60] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- Zhi Yang
- School
of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
| | - Yacine Hemar
- School
of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
- Institute
of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
- The Riddet Institute, Palmerston North 4442, New Zealand
| | - Loic Hilliou
- Institute
for Polymers and Composites/I3N, University of Minho, Campus de Azurém, 4800-058 Guimarães, Portugal
| | - Elliot P. Gilbert
- Bragg
Institute, Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Duncan J. McGillivray
- School
of Chemical Sciences, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand
- Institute
of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
- The MacDiarmid Institute, Palmerston
North 4442, New Zealand
| | - Martin A. K. Williams
- Institute
of Fundamental Sciences, Massey University, Palmerston North 4442, New Zealand
- The Riddet Institute, Palmerston North 4442, New Zealand
- The MacDiarmid Institute, Palmerston
North 4442, New Zealand
| | - Sahraoui Chaieb
- Division
of Physical Sciences and Engineering, King Abdullah University of Sciences and Technology (KAUST), Thuwal 23955-6900, Kingdom of Saudi Arabia
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Knobloch JJ, Nelson ARJ, Köper I, James M, McGillivray DJ. Oxidative Damage to Biomimetic Membrane Systems: In Situ Fe(II)/Ascorbate Initiated Oxidation and Incorporation of Synthetic Oxidized Phospholipids. Langmuir 2015; 31:12679-12687. [PMID: 26517192 DOI: 10.1021/acs.langmuir.5b02458] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [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
Damage to cellular membranes from oxidative stress has been implicated in aging related diseases. We report the effects of oxidative damage on the structure and properties of biomimetic phospholipid membrane systems. Two oxidation methods were used, in situ oxidation initiated using Fe(II) and ascorbate, and the incorporation of a synthetic "oxidized" phospholipid, PoxnoPC, into biomimetic membranes. The biomimetic systems employed included multibilayer stacks, tethered bilayers, and phospholipid monolayers studied using a combination of reflectometry, attenuated total reflection infrared spectroscopy, electrochemical impedance spectroscopy, and neutron diffraction. We show that oxidation with Fe(II) and ascorbate caused an increase in the order of the membrane, attributed to cross-linking of the phospholipids, and a change in the electrical permeability of the membrane, but no significant impact on the thickness or completeness of the membrane. Incorporation of PoxnoPC, on the other hand, had a larger impact on the structure of the membrane. Inversion of the aldehyde-terminated truncated sn-2 chain of PoxnoPC into the head group region was observed, along with a slight decrease in the thickness and order of the membrane.
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Affiliation(s)
- Jacqueline J Knobloch
- School of Chemical Sciences, The University of Auckland , Private Bag 92019, Auckland 1142, New Zealand
| | - Andrew R J Nelson
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
| | - Ingo Köper
- Centre for Nanoscale Science and Technology, School of Chemical and Physical Sciences, Flinders University , GPO 2100, Adelaide 5001, Australia
| | - Michael James
- Australian Nuclear Science and Technology Organisation, Locked Bag 2001, Kirrawee DC, NSW 2232, Australia
- Australian Synchrotron, 800 Blackburn Road, Clayton, Victoria 3168, Australia
| | - Duncan J McGillivray
- School of Chemical Sciences, The University of Auckland , Private Bag 92019, Auckland 1142, New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology, P.O. Box 600, Wellington 6140, New Zealand
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Shahlori R, Waterhouse GIN, Nelson ARJ, McGillivray DJ. Morphological, chemical and kinetic characterisation of zein protein-induced biomimetic calcium phosphate films. J Mater Chem B 2015; 3:6213-6223. [DOI: 10.1039/c5tb00702j] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
A zein protein layer was used to mineralize thin films of calcium phosphate at the air–solution interface producing an iridescent mineral film with novel nano-morphology.
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Affiliation(s)
- Rayomand Shahlori
- School of Chemical Sciences
- University of Auckland
- Auckland 1142
- New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology
| | - Geoffrey I. N. Waterhouse
- School of Chemical Sciences
- University of Auckland
- Auckland 1142
- New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology
| | - Andrew R. J. Nelson
- Bragg Institute
- Australian Nuclear Science and Technology Organisation
- Australia
| | - Duncan J. McGillivray
- School of Chemical Sciences
- University of Auckland
- Auckland 1142
- New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology
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Yang Z, Chaieb S, Hemar Y, de Campo L, Rehm C, McGillivray DJ. Investigating linear and nonlinear viscoelastic behaviour and microstructures of gelatin-multiwalled carbon nanotube composites. RSC Adv 2015. [DOI: 10.1039/c5ra22744e] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The linear and nonlinear rheology of physically-crosslinked-gelatin gel-multiwalled carbon nanotube (MWNT), chemically-crosslinked-gelatin gel-MWNT, and chemically–physically-crosslinked-gelatin gel-MWNT composites, are investigated.
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Affiliation(s)
- Zhi Yang
- School of Chemical Sciences
- University of Auckland
- Auckland 1142
- New Zealand
| | - Sahraoui Chaieb
- Division of Physical Sciences and Engineering
- King Abdullah University of Science and Technology (KAUST)
- Thuwal
- Kingdom of Saudi Arabia
| | - Yacine Hemar
- School of Chemical Sciences
- University of Auckland
- Auckland 1142
- New Zealand
- The Riddet Institute
| | - Liliana de Campo
- Bragg Institute
- Australian Nuclear Science and Technology Organisation
- Kirrawee DC
- Australia
| | - Christine Rehm
- Bragg Institute
- Australian Nuclear Science and Technology Organisation
- Kirrawee DC
- Australia
| | - Duncan J. McGillivray
- School of Chemical Sciences
- University of Auckland
- Auckland 1142
- New Zealand
- MacDiarmid Institute for Advanced Materials and Nanotechnology
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Reynolds PA, McGillivray DJ, Mata JP, Yaron PN, White JW. The stability of high internal phase emulsions at low surfactant concentration studied by small angle neutron scattering. J Colloid Interface Sci 2010; 349:544-53. [PMID: 20573351 DOI: 10.1016/j.jcis.2010.05.082] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2010] [Revised: 05/21/2010] [Accepted: 05/25/2010] [Indexed: 11/24/2022]
Abstract
The changes in structure of high internal phase emulsions at low concentrations and at elevated temperature are reported for comparison with the same emulsions under conditions well away from instability. Small angle neutron scattering measurements on aqueous ammonium nitrate droplets dispersed in hexadecane and stabilized by very small quantities of a polyisobutylene-based surfactant (PIBSA) as well as related inverse micellar solutions in hexadecane, have been made as a function of temperature and surfactant concentration. Experimental conditions here favour larger and more deformable droplets than in previous studies. Besides the expected micelles and adsorbed surfactant, planar bilayers of micron lateral extent between touching droplets cover 20% of the droplet surface. Another difference from previous experiments is that the oil phase in the emulsions, and corresponding inverse micellar solutions are different in micellar radii and composition. The differences, and changes with surfactant concentration and temperature, are attributed to fractionation of the polydisperse PIBSA in the emulsions, but not the inverse micellar solutions. At low PIBSA concentration and high temperature the SANS shows emulsion decomposing into separate oil and aqueous phases. This occurs when the micelle concentration reaches a very small but measurable value. The inverse micelles may suppress by steric action long wavelength unstable capillary waves in the bilayers. Depletion repulsion forces here have a minor role in the emulsion stabilization.
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Affiliation(s)
- Philip A Reynolds
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia.
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Yaron PN, Reynolds PA, McGillivray DJ, Mata JP, White JW. Nano- and Microstructure of High-Internal Phase Emulsions Under Shear. J Phys Chem B 2010; 114:3500-9. [DOI: 10.1021/jp9084525] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Peter N. Yaron
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, Department of Chemistry, The University of Auckland, Auckland 1142, New Zealand, and Bragg Institute, ANSTO, PMB 1, Menai, New South Wales 2234, Australia
| | - Philip A. Reynolds
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, Department of Chemistry, The University of Auckland, Auckland 1142, New Zealand, and Bragg Institute, ANSTO, PMB 1, Menai, New South Wales 2234, Australia
| | - Duncan J. McGillivray
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, Department of Chemistry, The University of Auckland, Auckland 1142, New Zealand, and Bragg Institute, ANSTO, PMB 1, Menai, New South Wales 2234, Australia
| | - Jitendra P. Mata
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, Department of Chemistry, The University of Auckland, Auckland 1142, New Zealand, and Bragg Institute, ANSTO, PMB 1, Menai, New South Wales 2234, Australia
| | - John W. White
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia, Department of Chemistry, The University of Auckland, Auckland 1142, New Zealand, and Bragg Institute, ANSTO, PMB 1, Menai, New South Wales 2234, Australia
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Smith MB, McGillivray DJ, Genzer J, Lösche M, Kilpatrick PK. Neutron reflectometry of supported hybrid bilayers with inserted peptide. Soft Matter 2010; 6:862-865. [PMID: 21274414 PMCID: PMC3026316 DOI: 10.1039/b915800f] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The insertion of a synthetic amphiphilic, α-helical peptide into a supported hybrid bilayer membrane (HBM) was studied by neutron reflectometry to elucidate the resulting nanostructure. The HBM consisted of a self-assembled monolayer of perdeuterated octadecanethiol on gold and an overlying leaflet of acyl-deuterated phosphatidylcholine (d-DMPC). Using contrast variation, several reflectivity spectra were recorded for each step of film fabrication, and simultaneously modeled. This analysis indicated that peptide insertion into the DMPC lipid leaflet is the likeliest mode of incorporation.
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Affiliation(s)
- Matthew B. Smith
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | | | - Jan Genzer
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
| | - Mathias Lösche
- National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR), Gaithersburg, Maryland, USA
- Physics Department, Carnegie Mellon University, Pittsburgh, Pennsylvania, USA
| | - Peter K. Kilpatrick
- Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA
- Department of Chemical and Biomolecular Engineering, University of Notre Dame, 257 Fitzpatrick Hall, Notre Dame, IN, 46556, USA
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Reynolds PA, McGillivray DJ, Jackson AJ, White JW. Ultra-small-angle neutron scattering: a tool to study packing of relatively monodisperse polymer spheres and their binary mixtures. Phys Rev E Stat Nonlin Soft Matter Phys 2009; 80:011301. [PMID: 19658692 DOI: 10.1103/physreve.80.011301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/28/2008] [Revised: 05/12/2009] [Indexed: 05/28/2023]
Abstract
We measured ultra-small-angle neutron scattering (USANS) from polymethylmethacrylate spheres tamped down in air. Two slightly polydisperse pure sphere sizes (1.5 and 7.5 microm diameters) and five mixtures of these were used. All were loose packed (packing fractions of 0.3-0.6) with nongravitational forces (e.g., friction) important, preventing close packing. The USANS data are rich in information on powder packing. A modified Percus-Yevick fluid model was used to parametrize the data-adequately but not well. The modifications required the introduction of small voids, less than the sphere size, and a parameter reflecting substantial deviation from the Percus-Yevick prediction of the sphere-sphere correlation function. The mixed samples fitted less well, and two further modifying factors were necessary. These were local inhomogeneities, where the concentration of same-size spheres, both large and small, deviated from the mean packing, and a factor accounting for the presence within these "clusters" of self-avoidance of the large spheres (that is, large spheres coated with more small spheres than Percus-Yevick would predict). The overall deviations from the hard-sphere Percus-Yevick model that we find here suggest that fluid models of loose packed powders are unlikely to be successful but lay the ground work for future theoretical and computational works.
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Affiliation(s)
- Philip A Reynolds
- Research School of Chemistry, The Australian National University, Canberra, Australian Capital Territory 0200, Australia
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Abstract
We report the creation of air/oil/water interfaces with variable-thickness oil films using polyisobutylene-based (PIB) surfactants cospread with long-chain paraffinic alkanes on clean water surfaces. The resultant stable oil layers are readily measurable with simple surface techniques, exhibit physical densities the same as expected for bulk oils, and are up to approximately 100 A thick above the water surface as determined using X-ray reflectometry. This provides a ready system for studying the competition of surfactants at the oil/water interface. Results from the competition of a nonionic polyamide surfactant or an anionic sodium dodecyl sulfate with the PIB surfactant are reported. However, this smooth oil layer does not account for the total volume of spread oil nor is the increase in thickness proportional to the film compression. Brewster angle microscopy (BAM) reveals surfactant and oil structures on the scale of 1 to 10 microm at the interface. At low surface pressure (pi < 24 mN m(-1)) large, approximately 10 microm inhomogeneities are observed. Beyond a phase transition observed at pi approximately = 24 mN m(-1), a structure with a spongy appearance and a microscale texture develops. These structures have implications for understanding the microstructure at the oil/water interface in emulsions.
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Affiliation(s)
- Duncan J McGillivray
- Research School of Chemistry, Australian National University, Canberra, ACT 0200, Australia
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McGillivray DJ, Valincius G, Heinrich F, Robertson JWF, Vanderah DJ, Febo-Ayala W, Ignatjev I, Lösche M, Kasianowicz JJ. Structure of functional Staphylococcus aureus alpha-hemolysin channels in tethered bilayer lipid membranes. Biophys J 2009; 96:1547-53. [PMID: 19217871 DOI: 10.1016/j.bpj.2008.11.020] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2008] [Accepted: 11/18/2008] [Indexed: 11/24/2022] Open
Abstract
We demonstrate a method for simultaneous structure and function determination of integral membrane proteins. Electrical impedance spectroscopy shows that Staphylococcus aureus alpha-hemolysin channels in membranes tethered to gold have the same properties as those formed in free-standing bilayer lipid membranes. Neutron reflectometry provides high-resolution structural information on the interaction between the channel and the disordered membrane, validating predictions based on the channel's x-ray crystal structure. The robust nature of the membrane enabled the precise localization of the protein within 1.1 A. The channel's extramembranous cap domain affects the lipid headgroup region and the alkyl chains in the outer membrane leaflet and significantly dehydrates the headgroups. The results suggest that this technique could be used to elucidate molecular details of the association of other proteins with membranes and may provide structural information on domain organization and stimuli-responsive reorganization for transmembrane proteins in membrane mimics.
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Affiliation(s)
- Duncan J McGillivray
- National Institute of Standards and Technology (NIST) Center for Neutron Research, Gaithersburg, Maryland, USA
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Holt SA, Le Brun AP, Majkrzak CF, McGillivray DJ, Heinrich F, Lösche M, Lakey JH. An ion-channel-containing model membrane: structural determination by magnetic contrast neutron reflectometry. Soft Matter 2009; 5:2576-2586. [PMID: 21311730 PMCID: PMC3035324 DOI: 10.1039/b822411k] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
To many biophysical characterisation techniques, biological membranes appear as two-dimensional structures with details of their third dimension hidden within a 5 nm profile. Probing this structure requires methods able to discriminate multiple layers a few Ångströms thick. Given sufficient resolution, neutron methods can provide the required discrimination between different biochemical components, especially when selective deuteration is employed. We have used state-of-the-art neutron reflection methods, with resolution enhancement via magnetic contrast variation to study an oriented model membrane system. The model is based on the Escherichia coli outer membrane protein OmpF fixed to a gold surface via an engineered cysteine residue. Below the gold is buried a magnetic metal layer which, in a magnetic field, displays different scattering strengths to spin-up and spin-down neutrons. This provides two independent datasets from a single biological sample. Simultaneous fitting of the two datasets significantly refines the resulting model. A β-mercaptoethanol (βME) passivating surface, applied to the gold to prevent protein denaturation, is resolved for the first time as an 8.2 ± 0.6 Å thick layer, demonstrating the improved resolution and confirming that this layer remains after OmpF assembly. The thiolipid monolayer (35.3 ± 0.5 Å), assembled around the OmpF is determined and finally a fluid DMPC layer is added (total lipid thickness 58.7 ± 0.9 Å). The dimensions of trimeric OmpF in isolation (53.6 ± 2.5 Å), after assembly of lipid monolayer (57.5 ± 0.9 Å) and lipid bilayer (58.7 ± 0.9 Å), are precisely determined and show little variation.
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Affiliation(s)
- Stephen A. Holt
- ISIS, Rutherford Appleton Laboratory, Science and Technology Facilities Council, Didcot, OX11 0QX, UK
| | - Anton P. Le Brun
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK
| | - Charles F. Majkrzak
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899-6102, USA
| | - Duncan J. McGillivray
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899-6102, USA
| | - Frank Heinrich
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899-6102, USA
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, 15213-3890, USA
| | - Mathias Lösche
- NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland, 20899-6102, USA
- Department of Physics, Carnegie Mellon University, Pittsburgh, PA, 15213-3890, USA
| | - Jeremy H. Lakey
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle-upon-Tyne, NE2 4HH, UK
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Valincius G, Heinrich F, Budvytyte R, Vanderah DJ, McGillivray DJ, Sokolov Y, Hall JE, Lösche M. Soluble amyloid beta-oligomers affect dielectric membrane properties by bilayer insertion and domain formation: implications for cell toxicity. Biophys J 2008; 95:4845-61. [PMID: 18515395 PMCID: PMC2576380 DOI: 10.1529/biophysj.108.130997] [Citation(s) in RCA: 161] [Impact Index Per Article: 10.1] [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: 04/01/2008] [Accepted: 05/09/2008] [Indexed: 12/30/2022] Open
Abstract
It is well established that Alzheimer's amyloid beta-peptides reduce the membrane barrier to ion transport. The prevailing model ascribes the resulting interference with ion homeostasis to the formation of peptide pores across the bilayer. In this work, we examine the interaction of soluble prefibrillar amyloid beta (Abeta(1-42))-oligomers with bilayer models, observing also dramatic increases in ion current at micromolar peptide concentrations. We demonstrate that the Abeta-induced ion conductances across free-standing membranes and across substrate-supported "tethered" bilayers are quantitatively similar and depend on membrane composition. However, characteristic signatures of the molecular transport mechanism were distinctly different from ion transfer through water-filled pores, as shown by a quantitative comparison of the membrane response to Abeta-oligomers and to the bacterial toxin alpha-hemolysin. Neutron reflection from tethered membranes showed that Abeta-oligomers insert into the bilayer, affecting both membrane leaflets. By measuring the capacitance of peptide-free membranes, as well as their geometrical thicknesses, the dielectric constants in the aliphatic cores of 1,2-dioleoyl-sn-glycero-3-phosphocholine and 1,2-diphytanoyl-sn-glycero-3-phosphocholine bilayers were determined to be epsilon = 2.8 and 2.2, respectively. The magnitude of the Abeta-induced increase in epsilon indicates that Abeta-oligomers affect membranes by inducing lateral heterogeneity in the bilayers, but an increase in the water content of the bilayers was not observed. The activation energy for Abeta-induced ion transport across the membrane is at least three times higher than that measured for membranes reconstituted with alpha-hemolysin pores, E(a) = 36.8 vs. 9.9 kJ/mol, indicating that the molecular mechanisms underlying both transport processes are fundamentally different. The Abeta-induced membrane conductance shows a nonlinear dependence on the peptide concentration in the membrane. Moreover, E(a) depends on peptide concentration. These observations suggest that cooperativity and/or conformational changes of the Abeta-oligomer particles upon transfer from the aqueous to the hydrocarbon environment play a prominent role in the interaction of the peptide with the membrane. A model in which Abeta-oligomers insert into the hydrophobic core of the membrane-where they lead to a local increase in epsilon and a concomitant reduction of the membrane barrier-describes the experimental data quantitatively.
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Affiliation(s)
- Gintaras Valincius
- Department of Bioelectrochemistry and Biospectroscopy, Institute of Biochemistry, Vilnius, Lithuania
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Perriman AW, Henderson MJ, Evenhuis CR, McGillivray DJ, White JW. Effect of the Air−Water Interface on the Structure of Lysozyme in the Presence of Guanidinium Chloride. J Phys Chem B 2008; 112:9532-9. [DOI: 10.1021/jp800354r] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Adam W. Perriman
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
| | - Mark J. Henderson
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
| | - Christian R. Evenhuis
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
| | - Duncan J. McGillivray
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
| | - John W. White
- Research School of Chemistry, The Australian National University, Canberra, ACT 0200, Australia
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Knoll W, Naumann R, Friedrich M, Robertson JWF, Lösche M, Heinrich F, McGillivray DJ, Schuster B, Gufler PC, Pum D, Sleytr UB. Solid supported lipid membranes: new concepts for the biomimetic functionalization of solid surfaces. Biointerphases 2008; 3:FA125. [PMID: 20408662 PMCID: PMC2876326 DOI: 10.1116/1.2913612] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Surface-layer (S-layer) supported lipid membranes on solid substrates are interfacial architectures mimicking the supramolecular principle of cell envelopes which have been optimized for billions of years of evolution in most extreme habitats. The authors implement this biological construction principle in a variety of layered supramolecular architectures consisting of a stabilizing protein monolayer and a functional phospholipid bilayer for the design and development of new types of solid-supported biomimetic membranes with a considerably extended stability and lifetime-compared to existing platforms-as required for novel types of bioanalytical sensors. First, Langmuir monolayers of lipids at the water/air interface are used as test beds for the characterization of different types of molecules which all interact with the lipid layers in various ways and, hence, are relevant for the control of the structure, stability, and function of supported membranes. As an example, the interaction of S-layer proteins from the bulk phase with a monolayer of a phospholipid synthetically conjugated with a secondary cell wall polymer (SCWP) was studied as a function of the packing density of the lipids in the monolayer. Furthermore, SCWPs were used as a new molecular construction element. The exploitation of a specific lectin-type bond between the N-terminal part of selected S-layer proteins and a variety of glycans allowed for the buildup of supramolecular assemblies and thus functional membranes with a further increased stability. Next, S-layer proteins were self-assembled and characterized by the surface-sensitive techniques, surface plasmon resonance spectroscopy and quartz crystal microbalance with dissipation monitoring. The substrates were either planar gold or silicon dioxide sensor surfaces. The assembly of S-layer proteins from solution to solid substrates could nicely be followed in-situ and in real time. As a next step toward S-layer supported bilayer membranes, the authors characterized various architectures based on lipid molecules that were modified by a flexible spacer separating the amphiphiles from the anchor group that allows for a covalent coupling of the lipid to a solid support, e.g., using thiols for Au substrates. Impedance spectroscopy confirmed the excellent charge barrier properties of these constructs with a high electrical resistance. Structural details of various types of these tethered bimolecular lipid membranes were studied by using neutron reflectometry. Finally, first attempts are reported to develop a code based on a SPICE network analysis program which is suitable for the quantitative analysis of the transient and steady-state currents passing through these membranes upon the application of a potential gradient.
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Affiliation(s)
- W Knoll
- Max Planck Institute for Polymer Research, Ackermannweg 10, D-55021 Mainz, Germany.
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Valincius G, McGillivray DJ, Febo-Ayala W, Vanderah DJ, Kasianowicz JJ, Lösche M. Enzyme activity to augment the characterization of tethered bilayer membranes. J Phys Chem B 2007; 110:10213-6. [PMID: 16722717 DOI: 10.1021/jp0616516] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The rate of Ca2+ -triggered phospholipase A2 (PLA2) degradation of tethered bilayer membranes (tBLMs), composed of a synthetic lipid, beta-mercaptoethanol, and palmitoyloleoylphosphatidylcholine (POPC), is approximately 80 times greater than for those prepared with diphytanoylphosphatidylcholine (DPhyPC). Electrochemical impedance spectroscopy (EIS) and neutron reflectivity (NR) data indicate complete, water-free tBLMs that exhibit near ideal capacitive behavior and the presence of a water reservoir in the bilayer subspace proximal to the substrate (Au) surface for both tBLMs. Together these data indicate that the POPC and the DPhyPC tBLMs are structurally similar along the surface normal but markedly different at the outer leaflet/solution interface and that PLA2 is a sensitive probe of short length scale structural differences not revealed by EIS and NR.
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Abstract
Boundary lubrication, in which the rubbing surfaces are coated with molecular monolayers, has been studied extensively for over half a century. Such monolayers generally consist of amphiphilic surfactants anchored by their polar headgroups; sliding occurs at the interface between the layers, greatly reducing friction and especially wear of the underlying substrates. This process, widespread in engineering applications, is also predicted to occur in biological lubrication via phospholipid films, though few systematic studies on friction between surfactant layers in aqueous environments have been carried out. Here we show that the frictional stress between two sliding surfaces bearing surfactant monolayers may decrease, when immersed in water, to as little as one per cent or less of its value in air (or oil). We attribute this to the shift of the slip plane from between the surfactant layers, to the surfactant/substrate interface. The low friction would then be due to the fluid hydration layers surrounding the polar head groups attached to the substrate. These results may have implications for future technological and biomedical applications.
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Affiliation(s)
- Wuge H Briscoe
- Physical and Theoretical Chemistry Laboratory, University of Oxford, South Parks Road, Oxford OX1 3QZ, UK
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Pittler J, Bu W, Vaknin D, Travesset A, McGillivray DJ, Lösche M. Charge inversion at minute electrolyte concentrations. Phys Rev Lett 2006; 97:046102. [PMID: 16907594 DOI: 10.1103/physrevlett.97.046102] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2006] [Indexed: 05/11/2023]
Abstract
Anionic dimyristoylphosphatidic acid monolayers spread on LaCl3 solutions reveal strong cation adsorption and a sharp transition to surface overcharging at unexpectedly low bulk salt concentrations. We determine the surface accumulation of La3+ with anomalous x-ray reflectivity and find that La3+ compensates the lipid surface charge by forming a Stern layer with approximately 1 La3+ ion per 3 lipids below a critical bulk concentration, ct approximately 500 nM. Above ct, the surface concentration of La3+ increases to a saturation level with approximately 1 La3+ per lipid, thus implying that the total electric charge of the La3+ exceeds the surface charge. This overcharge is observed at approximately 4 orders of magnitude lower concentration than predicted in ion-ion correlation theories. We suggest that transverse electrostatic correlations between mobile ions and surface charges (interfacial Bjerrum pairing) may contribute to the charge inversion.
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Affiliation(s)
- J Pittler
- Institute of Experimental Physics I, University of Leipzig, D-04103 Leipzig, Germany
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Dura JA, Pierce DJ, Majkrzak CF, Maliszewskyj NC, McGillivray DJ, Lösche M, O'Donovan KV, Mihailescu M, Perez-Salas U, Worcester DL, White SH. AND/R: Advanced neutron diffractometer/reflectometer for investigation of thin films and multilayers for the life sciences. Rev Sci Instrum 2006; 77:74301-7430111. [PMID: 21892232 PMCID: PMC3164984 DOI: 10.1063/1.2219744] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
An elastic neutron scattering instrument, the advanced neutron diffractometer/reflectometer (AND/R), has recently been commissioned at the National Institute of Standards and Technology Center for Neutron Research. The AND/R is the centerpiece of the Cold Neutrons for Biology and Technology partnership, which is dedicated to the structural characterization of thin films and multilayers of biological interest. The instrument is capable of measuring both specular and nonspecular reflectivity, as well as crystalline or semicrystalline diffraction at wave-vector transfers up to approximately 2.20 Å(-1). A detailed description of this flexible instrument and its performance characteristics in various operating modes are given.
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Affiliation(s)
- Joseph A. Dura
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Mail Stop 8562, Gaithersburg, Maryland 20899-8562
| | - Donald J. Pierce
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Mail Stop 8562, Gaithersburg, Maryland 20899-8562
| | - Charles F. Majkrzak
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Mail Stop 8562, Gaithersburg, Maryland 20899-8562
| | - Nicholas C. Maliszewskyj
- NIST Center for Neutron Research, National Institute of Standards and Technology, 100 Bureau Drive, Mail Stop 8562, Gaithersburg, Maryland 20899-8562
| | | | - Mathias Lösche
- Department of Physics, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213
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Affiliation(s)
- Stephen A. Holt
- Research School of Chemistry, Australian National University, Canberra, ACT 0200 Australia, and Cooperative Research Centre for Bioproducts, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Duncan J. McGillivray
- Research School of Chemistry, Australian National University, Canberra, ACT 0200 Australia, and Cooperative Research Centre for Bioproducts, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - Simon Poon
- Research School of Chemistry, Australian National University, Canberra, ACT 0200 Australia, and Cooperative Research Centre for Bioproducts, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
| | - John W. White
- Research School of Chemistry, Australian National University, Canberra, ACT 0200 Australia, and Cooperative Research Centre for Bioproducts, School of Botany, University of Melbourne, Parkville, VIC 3010, Australia
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